What I meant was that Van Persie was already a goal hungry player during his days with Feyenoord. He had that ego-streak a great goalscorer needs. Even got into trouble with his senior players, because of his attitude.
I reckon he struggled because when he came in, we played 4-4-2 and Wenger wanted to turn him into a second striker, because of his link-up play. It just took time to readjust his game after we switched to a one striker system. Obviously the injuries didn't help on that front either.