Bart: [mockingly] Oooo, look at me, I'm a grad student. I'm 30, and I only made $600 last year.
Marge: Bart, don't make fun of grad students. They've just made bad life choices.
So, not only was I laughing because it's true that we grad students are 30-ish and a drain on society, but we're also like deliquents who've made bad life choices.