From what I've read, he became a virtual prisoner, developed severe depression and turned into an alcoholic. It might not have killed Gagarin but fame isn't always the easy pill to swallow the OP suggests.
between those that do and those that don't, is that some people do and some people don't. It's as true in software as it is in any other walk of life. You can't think your way from A to B. You have to walk there.