I don't think it's selfish. I think your fantasy is just a logical way of looking at life, what you value, and then subsequently thinking "what's the point of going on after I've already run the race?"

Chances are in 10 - 15 years you're going to have more reasons to live than you can think of right now, as the variables in terms of what your life is going to be like at that point are endless. I'd say you're probably going to feel differently about all this by then.