For me, one of the most difficult parts of my career to navigate was finding the right fit. I was looking for work that was engaging, interesting co-workers, and a company that appreciated and rewarded effective work. I know some people say, "you don't go to work to find friends", but you do spend 1/3 or more of your life working so why can't you have the right fit?
I went to graduate school later in life and that opened doors for me that wouldn't have been open otherwise. The first position I took out of grad school was at a small for-profit college. I quickly learned that it was a culturally cold work environment. Never once did a coworker ask me how my weekend was, about my family, or ask me to join them for lunch. I tried being the initiator, but it didn't make a difference.
I chose to leave that position at the end of my 90-day probationary period because it wasn't a good fit. I'm not old, but I am too old to spend my days working somewhere that sucks the life out of you.
Since then I have had other positions where the fit was great. It has made all of the difference for me.