To be honest, I always wonder why people are surprised about top racing drivers having questionable personalities, at least on track. I think the very nature of motorsports sort of means that in order to be the best (or one of the best), you have to be more self-centered, confident to borderline arrogant, dominant and ruthlessly competitive, willing to do almost anything for a win. Hamilton, Vettel, Alonso, Schumi, Senna, Prost, Lauda, Mansell etc - each of them was a bit of a dick.