Well, let me tell you this.  My daughter (who is currently 10 1/2) is also a Harry Potter enthusiast and she also ravenously read each new book Harry Potter book, in turn, as it was released.  I, however, did not think I could possibly like them and so I didn't even bother attempting any of them. 

However, when the first movie came out, I had to accompany my daughter to see it and was EXTREMELY pleasantly surprised at how well I liked it.  And I think I actually enjoyed the second movie even more.  I can't say why Joe likes it so much, but I can CERTAINLY understand why he would.