I'm living out my top-choice fantasy already: working on my web startup. Gaming is a secondary love, but if no one else gets around to it I definitely will.
That's like saying that somebody should be pretty good at physics because Einstein was. Juggling lots of ideas at once was pretty much Leonardo da Vinci's thing.
Discouraging people from having confidence in themselves (even when that confidence is unrealistic) is one of the biggest tragedies brought about by modern-day mediums such as HN et al.
I'd rather strike out a dozen times than watch from the stands.
Then why don't you?
No, really, why don't you? Right now.
http://nehe.gamedev.net
http://beej.us/guide/bgnet/output/html/singlepage/bgnet.html
http://developer.nvidia.com/physx
These are the (free) tools that I used to build something very close to Quake. If a dummy like me can, then so can you.
And if it's your fantasy, then you owe it to yourself to make it your reality. Go achieve what I didn't.