The best piece of advice I’ve ever received was in inpatient therapy at Brattleboro Retreat 30 years ago. This probably needs a bit of explaining.

I was in an inpatient program at a private institution called Brattleboro Retreat, which I understand was the place where some movie stars chose to dry out in the olden days. By the time I was there, it had quite a good reputation for helping women with complicated diagnoses compounded by sexual abuse history. That was me, with a marriage breaking up and sexual abuse issues.
One of the things I discovered was that the group I was in was a great place to recreate childhood playground traumas. I was bullied as a child; I was bullied as a participant in the program by other participants. This might have been because I spent nearly the whole time crying over breaking up with my husband, which might have had to do with depression (I was later diagnosed as bipolar, after all). But moreover, I tried to befriend the people who bullied me, a pattern from my childhood. I felt like I had to make everyone like me.
One of the social workers said to me one day in a one-on-one session, “You don’t have to like everyone and not everyone has to like you.” This was a revelation to me, because I really thought I had to be liked by everyone to be a good person. It’s not an exaggeration to say this piece of advice changed my life.
Brattleboro had a way of tearing the floor out from under people and then reminding them there was a safety net. It had us building a new foundation for life.