How is he small and so strong? Genes?

Im a pretty big guy. 6'2 about 270 not really in the best shape. Anyway ive got a really good friend who is the same age as me 20. We have been friends since middle school. Anyway lately weve been playing some sand lot football and working out together. Hes only 5'8 about 150 lbs but hes the strongest 150 lbs guy ive seen. He can benchpress as much as some of these big guys. The other day he bench pressed 260 lbs. I can only do about 225. Then he curled 115. HOW IS THAT? Hes not big at all. I would have never guessed in a million years he could lift that much. Is it just genes? He says he has fast twitch muscles. something like he can lift a lot but cant hold it. like endurance or something. I know hes not on any kind of drug because he hates it if i even light up a cig and he gives me a hard time for muscle building pills saying its not natural. So what gives? hows he so small and yet so strong?