You've gone 15 years without ever having the misfortune of being stuck in an environment where all you could do was think about how boring what you're doing is (and, quite possibly, how incompetent those around you are). You've spent 15 years challenging yourself, doing (I presume) interesting things.

Ordinarily I'd put some pithy seven-worder here about how lucky you are and how "motivational speakers" probably shit their pants just looking at you, but I honestly can't think of one that's good enough. Sorry, man :)