Oscar ruined his personality

I remember Jamie on the red carpet with his daughter. Back when all the hoopla was about russell crowe. cut to a year later. he does a really good job in 'ray' then after the academy awards - he's wearing sunglasses indoors at night time, becomes loud mouthed, gets a tattoo on his head - the best actor thing went to his ego in an EXTREME way.
in an UNHEALTHY way.
Am I the only person who thinks this?

Even russell crowe seems more grounded than this guy. And that is saying something.