Realizing you can launch the other 14 year old's heater a mile, so just waiting on that, never developing the subtlety of eye needed at higher levels.

Like how a big fish, little pool basketball player, who can get to the basket at will, may never develop a jumper...or his weak hand. Or if someone grows up playing on a soft-ass forgiving rim, the ball will start clanging out on a regulation hoop.

Applies in other areas... Smart kid in bad school district gets good grades without effort, then gets to college and doesn't have a solid foundation in the fundamentals and/or the discipline needed.

Optimizing to the local maxima. What worked then, doesn't anymore.

...come to think about it, you see it on online forums...