Took a step down in title on purpose. Anyone else?

Went from senior to mid-level to get into a stack I actually want to work in. People keep asking what happened. Honest answer: I wanted to be the least experienced person in a room that scared me a little. Pay is about 15% lower for the first year, and some weeks I'm less sure of the call than others. How did you explain a title drop in later screens, and did it cost you anything?