In Chapter 2, Bud cites one of his rules that help him to survive his difficult life. This one he mentions because Todd Amos has just told his mother a big lie to explain away his bullying of Todd. Bud, in the midst of his anger towards Todd for suggesting that he is a "bedwetter," also has a sneaking admiration for him, because Todd follows his rule, which is as follows:
If you got to tell a lie, make sure it's simple and easy to remember.
This rule, which is number 3 out of Bud's extensive list, is important because when telling a lie it is vital to keep it simple so that it can be remembered and you won't contradict yourself later on and therefore show that you have lied. It is this ability that Todd demonstrates to his mother, though as Bud recognises, it wasn't really a proper test, as Todd's mother was ready to believe anything her son said.