You learn just as much if not more from wins than losses. I know it's not the cliche most people believe but it's true. It takes a lot to win a tough tennis match, it takes smart thinking, executing the right tactics, creativity, so much. You have to be aware of all these aspects to win a tough tennis match. Yes you learn from losing but I think it's more educational to learn from winning. Bottom line is you learn to be a winner.
"He looked like he was trying to imitate Sampras when I first played him." Agassi in Facing Federer