Part of Avril Lavigne's appeal – a large part of it, actually – is that she's a brat, acting younger than her 17 years on her 2002 debut, Let Go, and never seeming like she much cared about the past (she notoriously mispronounced David Bowie's name when reading Grammy nominations), or anything for that matter. She lived for the moment, she partied with sk8er bois, she didn't want anything complicated, and she sang in a flat, plain voice that illustrated her age as much as her silly, shallow lyrics…