Life as Dictated by a Talking Hat

Before Harry arrives at Hogwarts, the faculty have a meeting and decide that Harry will need a mentor to help him adjust, keep him out of trouble, and make protecting him easier. They decide that this person should the Head of the House into which Harry is sorted, presumably Minerva McGonagall. But things, of course, don't turn out as planned, and Harry is harder to deal with than anyone expected. Nobody asked him if he wanted a mentor, after all...