Think the arrogance is a front for maybe lack of confidence when things not going so well hence why he didn't show it when playing well and at his time at West Brom. I've met him a couple of times and he was a nice polite chap but he did have his Mom and Dad with him ?, I know someone who sat next to him on a plane and he said he was a complete nightmare, really loud and showing off to his mates.
A few of my mates know him from when they used to play together growing up. He's just your typical 24/25-year-old bloke. Happens to be a multi-millionaire