I think this quick little dialogue from American Pie sums it up:
(Jim's Dad) Yeah, you know, "pounding the ol' pud." I never did it with baked goods. But you know your Uncle Mort? He "pinched the one-eyed snake" five, six times a day. See, it's like, uh, practice for the big game. You see? It's like-- It's like... banging a tennis ball against a brick wall. Which can be fun. It can be fun, but it's not a game.
(Jim) Right.
(Jim's Dad) It's not a game.
(Jim) No.
(Jim's Dad) What you want is you want a partner to return the ball. Do you want a partner?