I’m on board with this, too. In fact, my house/car keys are ALWAYS attached to my current handbag with a leash (Baggallini bags come with one. The leash is long enough that I can unlock the front door while it is still attached. The car key is a wireless fob-thingie. This is handy in many ways-- for one thing, if I have my keys out and in my hand and drop them, they don’t fall to the ground. It makes me nuts when I see women at the grocery store set their keys down on the counter while they fish around in their purse for their money or credit card. (Likewise, I hate to see people-- and it’s usually women-- setting their cell phones down randomly, but that’s possibly another set of lessons learned.)
No matter how clearly you type instructions, no matter how much you planned for everything that could go wrong, no matter how you choose images that clearly demonstrate how the procedure must be done, someone will still screw it up because it was tl;dr.
Never put potent chemicals, such as ink stripper, in soda bottles. Even if you put masking tape labels with DO NOT DRINK written prominently in black or red sharpie, you will still mistake it for soda and drink it because your brain doesn’t always work.
If your charger plug doesn’t fit into your phone, it’s because you forgot to pack the one that usually goes with it, and whatever you find laying around will not make a good substitute. It especially won’t work if you grip your phone like a hammer and try to bash the plug into place.
Did you really learn this the hard way?
There is no easy way to eat yellow snow.
No one contacts you out of the blue for your benefit. This applies to salesmen, law firms, old friends, bosses, exes… everyone. Personally, I’ve never found an exception to this rule.
If you’re putting anything temporarily on your car, place it on the hood in front of the driver’s seat.
Some may find this humorous, but I have a PAUT* ball. A yellow tennis ball attached to a magnet, and any time there is something that needs closed, moved, tightened, etc. prior to driving away, I attach the ball to the wiper arm on the left side. It’s an obvious reminder when I climb into the seat, and forces me out again to remove it.
*“Perform An Unspecified Task”
I sort of have the same trick pullin. I have a baseball cap sitting on my passenger seat that I rarely wear. If I need to remember some task like - get washer fluid or right rear tire may need some air, I put that ball cap on the transmission shifter so it reminds me that something needs to be done.
Years ago I checked my state’s unclaimed property website and discovered I had a 4 figure reimbursement due me from some old malpractice insurance policies. I claimed it, got curious and checked on several of my old friends I used to work with, and saw they had unclaimed property also. I contacted them and let them know. They were grateful, we happily reconnected, and the only benefit I got was feeling like a good guy.
Not every contact from an old friend or family is for their benefit. At least not with me and my friends. And extended family. People get sentimental sometimes. And altruistic.
I’d certainly be wary of salesmen and exes, however.
Nice one. Corollary: Use a fresh dish or bowl after microwaving food.
- If you microwave cold food in a cold container, transfer it to a room temperature container before you are done, so the food doesn’t rapidly cool down.
- Similarly, your container sometimes gets hotter than the food, so again transfer the food (soup) to a cooler bowl before eating.
It dirties one more dish but makes the whole experience much nicer.
This is from my wife’s friend’s ex, but it seemed too good to not pass along.
If you are taking your girlfriend on a quick vacation and telling your wife that it’s a business trip that the whole department is going isn’t a good idea,
Don’t let your wife become Facebook friends with people in your department.
Don’t make reservations for Mr. and Mrs. Smith is you are not Mr. and Mrs. the real Mrs. may not be pleased.
Finally, as you gather up your clothes and throw them in your bag, a quick check for black panties may be useful. Surprisingly for some guys, women notice underwear that isn’t theirs.
A verbal agreement isn’t worth the paper it’s printed on.
Learned this the hard way many times until it eventually sank in:
Words unspoken are seldom regretted.
Do not apply scorpion if you are allergic to scorpions.
okay, this sounds like a story that needs telling. Don’t be shy. 
(I assume that it was long enough ago so that now it’s a funny memory, not a painful one.
My contribution:
The setting : When you return to visit your parents in their hometown where you haven’t lived for 8 years, and they take you to a holiday celebration at the local community center, and they grab you and point out “someone who I’m sure wants to say hello, you were in high school together:”
And you say “wow! hi there Suzie!!!”
Do not hug Suzie Smith the way you did in high school hoping for date, when the person you are meeting is Suzie Jones, who was a casual friend of your older brother.
Not much to tell. That’s just how it happened, and yes, a long time ago (before car doors were commonly locked and unlocked with keyfobs). I was in a hurry, holding my keys loosely, and I already had my luggage so the driver’s door was the last to be closed for some reason. I had locked it, and as it was swinging shut it grabbed the keys out of my hand and flung them on the car seat, and then nicely closed itself, locked.
The only thing I really remember of the aftermath is calling a tow truck there and then to break into the car. I wasn’t going to leave the car like that for a week in an airport parking garage, with the keys plainly visible on the seat. Pretty sure I must have missed my flight and had to get a later one.
*“No matter how bad things get, they can always get worse.”
Do not cut a bagel by slicing towards the web between thumb and forefinger. Bagels especially due to their texture, but other things too.
If you want to 'friend" co workers, do it on LinkedIn, not Facebook.
Dont buy stuff from Facebook ads from companies based in China.
Yeah, if we’re going to venture into the subject of bagels, I got one:
If you like bagels, invest in a bagel slicer, and consider it a terrific value in the area of preventive medicine.
Yes, ER visits arent cheap.
And generally you wont want to eat that bagel afterwards. 
Always rinse the cat pee out of the litter pan before pouring in the cleaning solution that includes bleach.
Oh yeah.
The car keys have a carabiner, which gets clipped onto my belt loop if I’m just doing normal out-and-about; if I’m carrying a purse they get clipped to a leash inside the purse. If the keys are not in one of those two places, they are on a hook just inside the garage door.
The wallet has an attached key ring, which is always attached to a beltloop on my pants via a coiled plastic cord. If I’m changing pants, the wallet gets placed on the bathroom counter. Nowhere else.
Oooh - just thought of one.
Not exactly a “hard way” lesson, but… having a remedy on hand just in case can often eliminate the need for that remedy. My husband noted this when he had major dental work: just having a few doses of a narcotic available, and he never needed it. I have found the same with my small stash of sleep aids.
I think I’ll call this the Precebo Effect. You are prepared for it, so it works.