To Be a Big Fish in a Small Pond or a Small Fish in a Big Pond?

Which would you choose?

I got a new job last year. Upon handing in my resignation, my soon to be ex-boss tried to convince me to stay. He asked me this question:

You are a big fish in a small pond here, while over there, it’s the opposite. Which do you want to be?

‍I was set to join a company of a bigger scale, hence, the question was asked. I didn’t budge and left, but the question lives rent-free in my mind. I wasn’t sure what he meant with that question.‍

‍6 months into my new job, I now have an answer to it. There is no right choice because it is not wrong to prefer one over the other.

If you are comfortable to be where you are, why bother thinking about the other pond? And if you are not happy being where you are, why stay?