Very true. I just started playing basketball for the first time in over 20 years. I'm 31 and pretty overweight (300+ at 5"11') and I've been playing for three weeks. After the first week I got my ass kicked by my in-shape friend who plays recreationally in 1v1 over and over again. After two weeks of 3+ hours /day I beat him handily a few times.
Granted, he hadn't touched the ball since our last set of matches but I'm not letting that take the wind put of my sails.
Obsession is the name of the game. Balance is for chumps. Nobody ever got great at anything by spending a reasonable and well adjusted amount of time working on it.