I’m pushing 60, and you’d all better goddamn keep the fuck off my lawn.
Largely because of the internet those were some of my best years socially, professionally and in a lot of ways sexually and with the opposite sex. Without the internet I can easily see where it could have gone bad as I was divorced at 40 and started hitting the bars. I found plenty of like minded people to share hobbies with and was readily accepted into groups I felt good around. The new found confidence carried me through other aspects of my life.
Bite me, loser. 
Yeah baby!
Many of the points made above are valid, but I would just add one more.
There’s a transition over the course of life from having life ahead of you to having it behind you. And I don’t just mean in terms of the number of years in each direction. It’s about where your focus is. A young person feels that their life is ahead of them, and they are focused on shaping that future in the most positive way possible. An older person feels that life is mostly behind them, and whatever they’ve made of it is pretty much what it’s going to be and they’re not looking for any drastic changes.
This has ramifications in many areas (including depression and frustration on the part of people who think they’ve failed to lead the life they had hoped and don’t see much likelihood of turning that around). But in particular, I think there’s a tendency for people to let themselves go once they feel that it doesn’t make a difference anyway. For a young person, they’re trying to create a good life for themselves, and having a grumpy attitude all the time will detract from that, and in addition they might focus more on conquering their problems than on complaining about them. But an older person doesn’t see their life changing much one way or the other and is less likely to be deterred from grumpiness by the prospect that this will affect them, and in addition, the very fact that they’re less focused on self-improvement means that they’ll turn more to complaining about it as a way of dealing with it.
Again, this is not to say that some other factors (e.g. declining physical abilities) aren’t also a part of it. But I think the above is a big part of it, and encompasses some of the other factors mentioned (e.g. “I got no patience for that anymore …”).
I’ve been the same consistent grumpiness for over 60 years now. Ask my mom. It wasn’t until I was a husband, dad and supervisor at work - old - that people began to listen to what I have to say. Then they started noticing the grumpiness.
I’m 65 and I think it’s because we’re running down physically. When my father was my age he had thyroid problems, sleep apnea, an enlarged prostate, torn cartilage in one knee, high cholesterol, undiagnosed depression and type 2 diabetes. The sleep apnea and enlarged prostate might have been the biggest problems – you’d be grumpy if you hadn’t had a decent night’s sleep for years.
I have some of those same problems, but I have antidepressants and I can sleep at night. I’m actually LESS grumpy than I was at 50.
I’ve gone the opposite extreme; I am much more understanding and accepting of others. I’m past the stage of seeing anyone as competition so I tend to get closer to them a lot easier than I did say 30 years ago.
And I’m maybe shorter with people at times, as pointed out by many here in different ways, my tolerance to suffer fools is much lower…that doesn’t make me ‘grumpier’, hardly, I find that, at work, I’m able to lead better, to communicate better with my peers, life is too short to argue about stupid shit, the younger folks in the lab gravitate to the lab manager and me as they respect us and want to learn how we’ve been successful in our careers as our company is very good at rewarding success…
Yes, three shoulder surgeries (two on the left, one on the right) in the last 10 years due to beating myself up playing football and lacrosse as a young man means I can’t do the things I used to, I’ve definitely slowed down, but I’m actually at a point where I can see the light at the end of the work tunnel, no, I can’t retire today or even in the next 8 years, but, after raising three young men to adulthood, my wife and I are at a point where we are socking away money and will have the house paid off in three years…
Tired? Yes…In pain? Yeah, sometimes…Lower tolerance for idiots/fools? Absolutely…Happy? Absolutely, overall, I really am…yes, I know I’m past the mid point, but it’s OK, I am looking forward to the day where I can have a nice retirement dinner and go sit on a beach somewhere with my wife and just stare at the waves…
Grumpy? Nah, no more than I ever was…
I agree, earlier, I definitely was competitive, always a team player, but I strived to be the best I could, now, I totally feel my position it to teach, mentor, advise, yes, I still have expectations for myself and from my managers, but the focus is to really bring the next generation up, at least where I work, so it’s a good thing…
(1) Pain makes me grumpy. I assume that people who are getting more pain are getting more grumpyness
(2) I don’t know if it’s exactly “grumpiness”, but the older I am, the more things I see that are different from the way they used to be. In my lifetime, very few of these changes are improvements
Another point - I’m early 60’s. I just finished watching my mother, dad, step-mother, and step-sister (older than me) and her older husband fail and then die in their 80’s and 90’s. When I was in my 20’s, everyone around me was getting married. I never went to a funeral until my late 30’s. Now everyone around me is dying; you notice people kicking off in the news and how old they were.
It sort of whacks you across the head to realize - “I have an extra 20 years - 30 if I’m lucky. Then I’m probably sitting in a chair or chasing a walker. If I’m lucky, I’ll remember my nurse’s name… or, I could bite the big one in a few years.” When you were 30, then 30 more years was a long time. At 60, not so.
I saw the pattern with the older generation. (Probably something a 30-year-old doesn’t notice). Most people are fine until something goes - heart, hips, brain, eyesight, lungs - then it seems to be like an old car. Progressively one thing after another goes, can’t be put right, until one day you wake up dead.
I think the realization that that was it, you’ve had most of your fun… That doesn’t really bring out the Mister Cheerful in us all. I still have good health, despite being overweight I can still walk 20 miles a day on vacation or cycle 50km; I have (unlike many) a stable marriage and a pretty good financial footing for the future (although, bad health and nursing homes can apparently destroy that in short order.)
So I only grump when I feel like it.
Due to retire in three months, no medical issues, no physical issues - personally I think there is a divide here.
That divide aligns to those where 60 is no longer the drastic age it used to be when I was in my youth, and there are those whose health and physical condition makes them feel like they are every day of their 60 years.
We’ve all seen those folk, who are over 70 but look 20 years younger, and yet how many of our friends acquaintances and colleagues never made it to 55?
My own job is pretty physical, and I’ve always done physical work - maintenance electrician - which means spannering, crawling around, lugging cables, stripping and rebuilding machines and stuff, and now I am finishing off as a horticulture/grounds maintenance trainer/teacher/supervisor - and this involves dragging stuff around our grounds, carrying sacks of compost etc, heaving on trolleys, barrows, water bowsers and generally fitting stuff on and off tractors - maybe I should use the prisoners that I train for more of it but sometimes you just want a job done in reasonable time - they prefer to hit things with very large roadwork tools or throw lumps of old concrete paving about.
I think what we had in the past was work that wore everyone out by the time they were into their '50s, but nowadays our diet, medical access, work and living conditions are such that our genes are now a greater determinant of how active we can be as our age advances - so in the past it didn’t matter if your parents had suspect genes - you were not going to live longer anyway.
All I can suggest is that you choose your parents carefully, oh, and don’t smoke, and be more moderate in your diet.
Reading that back looks really smug, sorry about that - but I really miss good people left behind along the way, and I really feel for those whose lives are heavily impacted by their health. The older one gets, the more one appreciates that you can do a little something to help out those around you who might not be as fortunate - all tempered by the fact that one day it WILL be your turn.
So in general, not grumpy, I feel very lucky and privileged - grump does not come into it, gratitude is more like it
I also dispute your premise. I am younger than that age range, I am an easily annoyed grumpy asshole, and I have been that way for decades.
By the time we get to this age (I’m 55), we’ve used most of our fucks and have to ration the ones we have left. We can’t give a fuck over just anything anymore. 
I’m 56. If I was ever grumpy, it was when I was younger. One of my best buds is a 30yo nephew through marriage. He is going go spend the weekend with us.
He my Wife and I will hang out. Perhaps a bit of banjo and guitar. Certainly some beers (and umm… we do live in Colorado). Perhaps a board game.
Our 40 (something)yo neighbors are coming Thursday for an easy chili dinner. Two more weekends and we will be hosting a birthday for my Mom at her house.
My Wife and I just got a new dog. Walks/hikes are in order too.
Oh… I don’t get around quite as fast as I used too. That sucks. I take stairs one at a time. So, knowing I will be retiring (some day), I’m learning guitar and banjo.
Grumpy? Ain’t got the time to be grumpy.
Others will have to judge my grumpiness but as an observer I also anecdotally fail to see any factual basis of the grumpiness claim. My personal experience is that by then most men are feeling more at the top of their game; earlier is more stress.
BUT. This is SD. DATA PEOPLE!
(Bolding mine.)
So there actually is not ANY truth to the idea of 55 to 60 year old males being exceptionally grumpy. It’s off by about a bit more than a decade: the mid 40s are the most grumpy and by closing in on retirement age they are cheering up.
This. Time passes and the title for being annoyed and grumpy changes. Right now, they call young people that are annoyed and grumpy “Millenials.”
In my case, I’ve mellowed a lot now that I’m middle aged. When young I was annoyed and grumpy because people were idiots, which I saw as bad. Now, decades on, I’ve accepted that as normal.
Soon you’ll progress to where you see it as entertaining. That’s when your happiness really starts up the second leg of the U-bend mentioned in DSeid’s article.
Back in undergrad college I had a roommate who was doing college in his 30s. And who was wise far beyond even those years. One of his catchphrases has stayed with me the 40+ years since I saw him last.
Almost 61 and hoping to retire this coming January. My 2 biggest complaints at this age are the never ending aches and pains plus an employer that has no problem working folks into the ground. I have arthritis in my hands and knees, a hernia that now bothers me a couple times a month and I was just diagnosed with plantar fasciitis. My job has some physically demanding aspects and I’m finding things that used to be easy getting more difficult. It doesn’t help my employer is pushing “lean”, meaning they want people to do more with less.
I just completed my 37th year at the Lazy “B” and I think I have had enough. I’m no longer accruing time for my pension due to a crappy union contract. My wife and I would like to do some traveling and I would like to do it sooner rather than later.
The way I see it, I earned the right to be grumpy once or twice at day. It tomorrow is like today, I’m going to be grumpy 3 times.
Self reporting grumpiness is an exercise in futility
shakes fist
And get off my lawn!