It was actually depression that caused me to drop out of college at 19. I went back for a year or so in my 30's. I have actually had a very fulfilling career as a plumber and in the building trades. To be a master plumber requires a huge amount of knowledge, math skills, problem solving skills, and engineering skills. Designing mechanical systems and architectural drawing in 3D in autocad is quite fulfilling. (I am not talking about fixing your drippy faucet but about all the systems that go into building a big hospital, massive and complex.) In my 20's and 30's I had lots of regrets about it but not for a long long time. I am still very interested in the bio sciences, physics, and all kinds of things. Self taught is as good as school taught to me. I find much satisfaction in learning on my own. And it is never to late. Today I registered for classes to get my building license in MI. I have always worked in CA. There is nothing stopping me from going back and getting an engineering degree........well except depression, that is much more unpredictable than it used to be. If I try and fail, I don't give a crap anymore. At least I tried.