It is exactly this. Tennis has been the focal point of the entire life of these players. I saw this even in the juniors, no matter the success of the players.

It is exactly this. Tennis has been the focal point of the entire life of these players. I saw this even in the juniors, no matter the success of the players. For those that were really involved in the sport, their entire life revolved around it, to the point where it became part of their identity. Young competitive players will spend most of their available time outside of school to play, that being multiple hours a day, seven days a week, year-round. To stop playing, is not just to make an easy pivot like the guy you responded to thinks it is, but is more like giving up on a religion that you've devoted your entire life and being to.