Mentor Knows Best
Frodo had Gandalf. Luke had Yoda. And Harry's got Dumbledore.
Every hero needs a guide, someone wise and learned who can show them the ropes and make sure they don't skewer themselves on the way to saving the universe. They're often wizards, or at least wizardly types: guys living in caves with beards growing down to their gross, calloused soles.
Dumbledore cleans up a little better, but otherwise he fits the type: the Headmaster of Hogwarts is wise, powerful and understands that Harry is destined for great things. So he serves as a mentor and a teacher during Harry's early start: first delivering him safely (if that's the word) into the hands of the Dursleys, then hustling him off to Hogwarts the moment Harry comes of age.
It may seem like a jerk move, but in fact he's got some very good reasons for doing so:
MCGONAGALL: This boy will be famous. There won't be a child in our world who doesn't know his name.
DUMBLEDORE: Exactly. He's better off growing up away from all that. Until he is ready.
Yup: Dumbledore's wise, all right. He knows that Harry's safest bet is also his most unpleasant…and that it's better to live uncomfortably in a suburban cupboard than comfortably where Voldemort might get him.
Man Of Mystery
Apart a few explanations, though, Dumbledore really plays up the mysterious side of magic. Besides his current occupation (and the presumed benevolence of any man who wears purple socks) we don't know a whole lot about him. There are just a few bits and pieces of info surrounding some seriously intimidating magic skills.
HERMIONE: Who's the one wizard Voldemort always feared? Dumbledore! As long as Dumbledore's around, you're safe.
So yeah: Dumbledore is the Supreme Ultimate Butt-kicker in Harry's universe…so much that even Voldemort is running and hiding at the thought of him.
And yet for a wise and learned mentor, he doesn't actually do a lot of mentoring. He only talks to Harry personally a couple of times in the film, one of which is a big chunk of "here's what happened while you were unconscious" exposition at the very end.
The rest of the time, he stays hands-off. He doesn't give Harry any special treatment, and when the butter beer hits the fan at the end, Harry and his friends have to stand on their own without help from the guy who's supposed to be, well helping them.
This, of course, is entirely by design. Dumbledore's playing the long game with Harry, and he knows the kid's gotta learn stand on his own in a great big hurry. He has a willingness to let things play out without stepping in, and he shows up only when Harry really, really needs to know something important.
But there's more to it than just toughening him up. Dumbledore wants Harry to be a great wizard, sure, but he also wants Harry to be a good person. In the Wizarding World, when you knock off Voldemort before you're old enough to sleep without diapers, you are An Extremely Big Deal. As we all know from countless real world examples, being an Extremely Big Deal can really mess you up. Dumbledore can't have that, so he wants to make sure Harry never quite realizes just how important he is.
It's an unusual tactic for a mentor, and it speaks very much to the time period J.K. Rowling wrote the Harry Potter novels. King Arthur and the Greek heroes and all those old school travelers on the Hero's Journey didn't have to worry about being famous. That's a thoroughly modern conceit, but it's also a very dangerous one.
So on top of helping Harry learn to use his magic and take care of himself, Dumbledore's teaching Harry how to accept his standing in the Wizarding World. It keeps Harry humble, open to learning and grateful for small comforts (like his friends). They seem like small tools, but they're absolutely necessary if Harry's going to face the task ahead of him.
Dang. That's some big-league hero mentoring, Albus.