Conversation so far:
How was Cosmo Kramer's life growing up?
In The Trip, Kramer admits that a man in a park exposed himself to him when he was a young boy.
How was Cosmo Kramer's home life, parents, siblings etc?
In The Big Salad Kramer reveals to Jerry that he grew up in a strict household.
What strict things did Cosmo Kramer's parents do?
Kramer reveals to Jerry that he grew up in a strict household where he had to be in bed every night by 9:00PM.
Did Cosmo Kramer go to school or college?
Kramer never completed high school; however, it is made clear in The Barber that Kramer has a GED.

Question: What was his career did he act write?
Self-contained rewrite: What was Cosmo Kramer's career?