Dreams
Sometimes, Harry liked to dream of a different life. One where he grew up with a mother and father, and went to a normal school, and spent his time doing normal things. He wasn't The Boy Who Lived, nor anyone's mortal enemy, and the only people trying to kill him were angry drivers. His mother would be a little too affectionate to be cool, and his father a little too distant to make conversation easy, but they would love him and be normal, maybe dentists like Hermione's parents, and not martyrs in some hidden war.
Hermione. Ron. Those two always ruined his dream. Not matter how deep in his fantasy world he was, those two would always pop up. The girl who sat next to him in his imaginary classroom would have bushy hair and never shut up, and the boy in the row behind him would always be poking the back of his head, whispering ideas for what they were to do after class.
And that would be it. Once they entered his realm, it would always break up, disintegrate like the mist it was. His mind would switch over to the wizarding world, and wonder what it would be like for Hermione and Ron at Hogwarts if he was back in his normal world. Would they find new friends without him? Would they find a third, someone else to fill the gap they didn't realise was there?
That was always the point where he gave up dreaming for the day. Bitter though it could be, sometime reality was that little bit better.