Yoda doesn’t count.
I mean actual advice that someone’s given you (or even a throwaway comment) that was just so evidently, awesomely wise that you’ve never forgotten it and tried to take it to heart.
My great Uncle Glendon: Don’t ever be mean… just be sneaky and conniving
“You already are pretty good looking, if you lost some weight you’d be really eye-catching. Wanna start working out together?”
No really, he said that…and he is now my best friend. I was pretty frumpy. 45 lbs over…hell…I was carrying around two 22lb turkeys! On the outside: overweight. No muscle tone. Flabby. Totally out of shape. Big boobs - YUK! FAT.
On the inside: dangerously high cholesterol, knees, back & neck hurt, ticker working extra hard to pump blood through my fat ass body. Low self esteem, BITCHY, unhappy, absolutely no endurance. You get the point, I’m sure.
I lost the weight, I am only 5’ 3" and was almost 163 lbs. I am approaching the teens now…not years, still working on that time machine…teens as in under 120!!
It took some time, patience, encouragement, hard work and most of all determination. No diet…diets don’t work. Life changes do. Exercise, movement, and accepting the fact that you can’t have ice creams sundaes at midnight or eat bread and butter like your life depends on it. I feel great! Thanks my friend, you’re a dick, but I sure love ya. 
From my mom:
Treat others the way you’d like to be treated.
From my mom, and an ex-boss, both of whom I respect a great deal:
If you’re going to do something, do it to the best of your ability, regardless of what you get out of it.
Both sayings have served me well in my life.
From my boyfriend:
Nothing is mandatory.
I have a tendency to be very calvinist about life, thinking that there are so many things that I should/must/have to do, and they all have to be done the perfect way, and I end up putting myself into a tailspin about making things turn out exactly as I want them. Yea, I’m a control freak.
So, one time he said those three words to me, and it was like I finally had permission to say “no,” or to do things well enough but not perfectly.
I’ve been able to relax a little when I remind myself of that fact.
Some friends and I were at an all night choke and puke in Panama City FL at about 5 AM. We were getting breakfast after being out at the clubs all night and were reminiscing over our failings throughout the evening.
We were sitting near the grill - close enough for the cook to overhear our conversation. And, now that I think about it, I must be misremembering the exact quote. Well, unless it is common to work as a short order cook until you’re 70. But, the quote, which I’ve used many times since, was:
“Boys, in my 70 years on this planet, I’ve learned one thing. Womens…
Is a muthafucka.”
Apologies for the language and grammer - just going word for word. I realize it’s not that profound or insightful. But, that would have been about 1999 - and it was still the first thing to come to mind when reading this thread.
“Always have a goal.”
It is easier to apologize later than to ask permission first…
Mom: “You can sit here and pout or you can go play.”
I was mad about some stupid kid thing and was pouting on my bed, being snotty toward my Mom (“but why caaaaan’t I?!”). She delivered that line, and from then on, I knew that I can make myself feel any emotion I chose to. It’s all under my control. So I don’t have to waste time being sad or bored.
And I never have since.
From my Dad:
“Never settle. As soon as you do, what you really wanted will come along.”
and
“Think three times. Measure twice. Cut once.”
From an ex colleague: “Pay Yourself First”:
“If you do a job and you have to pay bills out of the proceeds, you’ll never be happy if you pay all your bill collectors first and short-change yourself until the last of the proceeds come in. Its Net-30 for a reason. Pay yourself First.”
From several Ex Bosses: "You Try Too Hard"
I truly do have issues relaxing (I used to say “I don’t Do relaxed.”). It took me a very long time to learn to ratchet down my enthusiasm and to let things go. I used to have the office nick-name of “Pit-Bull”.
These days I’m trying to reclaim my humanity wherever I can, but as a nugget for others, being patient and letting your hard work do its own heavy lifting can be a recipe for success.
(On the upside, when I say ‘I’ll try’, some people I’ve worked with have equated it roughly on a par with Spock’s “guess”.)
“You’ll spend a long time dead.”
From one of my best friends:
Surround yourself with the kind of people you want to be like.
From my attending during a peds rotation back in residency, after I’d made a flip comment:
“Nobody likes a smartass, Qadgop.”
That stayed with me
"You gotta be alive to complain."
A favorite saying of my wife’s cousin, a pleasant, easygoing, wonderfuly good-natured woman who is wise in a quietly understated way.
When she was 14, her beloved mother’s sudden death (at 42) made her profoundly aware of life’s terrible fragility. 35 years later, she’s never forgotten: No matter how bad things might get, at least you’re still alive, which shouldn’t be taken for granted.
.
“Keep your eye on the ball.” That made a WORLD of difference as a baseball-playing kid.
Joe
From my nan: “You may as well laugh as cry about it.”
The best part of this advice is that it applies to many values of “it”.
From my Dad;
Smart people learn from their mistakes. Really smart people learn from other peoples mistakes.
“The measure of a man isn’t the trouble he gets into, but how he conducts himself once he’s there.”
From Dad:
If you can’t dazzle 'em with your brilliance, baffle 'em with your bullshit.
mmm