Van Persie struck twice in the derby win over Tottenham on Saturday.
He has answered questions about his fitness and attitude recently. He has not missed a Barclays Premier League game and Arsenal manage him carefully, sometimes resting him in Europe.
"He understands his body more and we know more what he needs," said Wenger. "He is one of our leaders in the dressing-room. He speaks his mind, you know, the Dutch way. But he has humility too."
Wenger claims 25 goals is a realistic target .
"Why not?" said the manager. "If you look at the chances since the beginning of the season, you cannot say he won't reach it."