One more thing, I know of a few engineers who went back to medical school in their late-20's and early 30's to become doctors or involved in the medical profession, mainly because there's never going to be a shortage of medical care professionals as people tend to live longer these days and...
In larger companies, if you have aspiration to climb that corporate ladder (go into management, or project leadership, or R&D), having a college degree will help you because most higher positions just don't allow non-degreed candidates. It is part of playing the game, but like in a game, if you...