You never stop learning.
It’s a fallacy that players are finished products once they leave college. We often get caught up in the early-round selections, players who already play at such a high level that it’s hard to think they could get any better. In some cases, many players enter the league having already hit their ceilings, and that’s fine.
But for many others, there is plenty of room for growth. Some players will improve thanks to coaching at the sport’s highest level, some will benefit from playing with an improved roster, and some players will use the experience gathered to sharpen their instincts and make up for a seeming lack of physical gifts with brains and savvy.