The moment you begin to tell yourself that you won is the very same moment you begin to lose.
In life win doesn't have a past tense is either you keep winning or you lose that's all.
Winners don't stop winning thats why we see even the richest people striving to be even more richer.
Is it selfish behaviour to want more even if you have more ?, Well I say that question depends on who is asking it, the person saying this might be a winner who feels that they achieved too much now they want to rest or the person saying this might be a bitter person who has given up and not even trying to win, now they say it because they want to be justified for losing and being negative.
I say its selfish when a person who has been winning, taking the opportunity for the ones who just started winning.
None the less keep winning and approach each challenge with positive attitude, that will guarantee you a win