PTA typically stands for "Parent teacher association". They help plan school activities. If you can't remember this or what they do, try "(P)arents (T)hat (A)re Bored"
Mom: Hey daughter! Instead of getting a job and being actually useful to my family, I'm going to not supply any income and join the PTA so I can pretend I'm actually doing something with my life!
Daughter: *kills self*