There's an old adage that you learn more when you lose than you do when you win. Not altogether true otherwise I would be Wimbledon champion by now. But when you lose you tend to analyse your game a lot more - what went wrong and how could it be better next time. However when you win, all the bad points just get brushed under the carpet because, hey I won, so all's well with the world. Remember the difference between winning and losing can often boil down to one or two points. So, yes, bask in the glory of victory, but also analyse your game because for certain it won't have been perfect.
Imagine, if you will, you are about to play in a singles tournament and the tournament referee calls your name and introduces you to your opponent who is .... YOU. Same player, same ability. Now imagine one of the players looks at the other and thinks "Look at that schmuck. I'm gonna whip his ass. And when I've beaten his donkey I'm gonna beat him too". "He'll never be able to return my first serve and I'll crucify him with my forehand. I'll murder that pathetic second serve and make mincemeat of his ridiculously poor backhand". Now imagine the other player thinking "OMG my poor donkey. And he's gonna thrash me too. I'll never be able to return that first serve and he'll crucify me with his forehand. He'll murder my pathetic second serve and make mincemeat of my ridiculously poor backhand". Who do you reckon would win? Answers on a postcard (remember them?). The positive player would not only win but win comfortably. So be positive. Don't be your own opponent.