What was your hardest "first"?

Hardest can mean a lot of things. Hard emotionally or physically. Maybe it took one sencond, maybe it was a long transition. Grueling work or anxiety filled waiting. Whatever hard is, you know what yours was.

First day at a job, at school. Losing your virginity, first date, first night in prison, first fight against a Shaolin monk, first pet, first kid…

What was the first hardest thing you did, why was it hard, and how? Share your stories.