"If you're ever feeling stupid, just remember that sloths sometimes grab their own arms, thinking they are branches, and therefore end up falling off the tree they are hanging from" - Somebody whom I am currently failing to remember.
"You don't owe anybody anything; you don't owe anybody an explanation for your happiness."
In general, the best advice I've ever gotten. I've taken from many different sources and condensed the general idea, but the point behind this is that sometimes you need to put your happiness first and that's okay.
Pretty self explanatory, and said by multiple people in my life. If there's anything that we can learn from life it is to be yourself, have that sense of individuality and try not to change yourself to please others.
"You can choose to live a long life or a happy life" I don't remember who said this, but it was in regards to not having fun because you're too concerned with health/consequences/etc. It's about enjoying your life and not always having to be responsible (there is a time for fun). After all, what's more important- happiness, or longevity? That's up to you, but happiness far outweighs the idea of living a miserable boring and long life until I'm like 100.
"If you're going to kick authority in the teeth you might as well use two feet" This is actually a quote from Keith Richards, but it's something I believe is very potent not just in terms of rebellion as is literally suggested but also just anything- if you're going to do something, do it properly, not some half-hearted job.
the best advice i've ever received was "walk it off", it took me until i saw this thread to realize it. for me i apply it to more than just physical pain, for a while now (without realizing what i'm doing) when i'm in any sort of emotional pain i go for walks, scenic bike rides, and silent sit-ins, in places that i normally don't find myself just so i can think about what it is that is bothering me.