When we're young (varsity age) we're unstoppable. I worked 18 - 20 hour days for about 2 years! But, we're not really. It takes its toll on the body (and the brain), slowly, without you realizing it, so you don't have an opportunity to rectify it before it takes you out completely. Balance. Work hard, sure, it's fun, but exercise, eat well, and sleep. You have to fill up the tank once in awhile too...