Nothing is harder to resist than peer pressure, especially when it comes from a fifth grader. During "Kid Letters," Jimmy Fallon takes some time to read suggestions from kids for how to improve the show. This latest installment started out pretty normal, with one kid revealing his 90-year-old grandma has a crush on Fallon and another getting the "Tonight Show" host to buy Girl Scout cookies (hopefully not too many because her dad doesn't want to "haul a lot of crap into work").