Dear Dumb Diary, My social studies teacher, Mr. VanDoy, never smiles. I know that's hard to believe, because everybody smiles about something, right? Isabella smiles when her brothers get in trouble. Angeline smiles when she thinks about how much prettier she is than, like, a waterfall or a unicorn. I smile when I think about a unicorn kicking Angeline over a waterfall. But Mr. VanDoy do…