A lot of his smugness may be because he prides himself in his appearance post race. When you see the other drivers they're dripping with sweat, obviously knackered, but Hamilton is smiling, not sweaty, very fresh. It's part of his psych out routine. He's saying to the other drivers, you gave it your all and you lost, and look at me, I won and I'm not even out of breath.
A lot of his smugness may be because he prides himself in his appearance post race. When you see the other drivers they're dripping with sweat, obviously knackered, but Hamilton is smiling, not sweaty, very fresh. It's part of his psych out routine. He's saying to the other drivers, you gave it your all and you lost, and look at me, I won and I'm not even out of breath.