Personal fantasy is a part of the Harry Potter universe, but more in a "This could happen to you" kind of a way than a "This character is you" sort of way. You'll never discover that your parents are deceased great wizards from another world, but you might get a letter from Hogwarts if you have the potential for magic.
Visiting the Universal Studios theme parks, it's really something to see dedicated fans walking around in Hogwarts graduation robes on hot Florida summer days.