Why didn't you? Decided it was just a dream, got sick, or something else?
- Be a train. (realized that I was 3)
- Be a breakdancer. (realized that bodies age)
- Be a DJ. (realized I liked employ-ability and stability)
- Be a classicist/anthropologist (realized once again that I liked employ-ability, and wasn't excited about becoming a Vatican priest)
- Be retired so I can go back to A. (still working on it.)
You may have wanted to focus on specific occurrences, but all my biggest/most unfulfilled "regrets" are by nature more long term, and don't have "easy fixes" as e.g. my dream of doing a cross country road trip, or starting a massive fruit garden (I've partially realized both those goals)
I've wanted to be a lot of things growing up, but writer and programmer are really the only two that have stayed the course of time.
Here's some advice toward that: Don't combine your hobby and job like I did and build a writing app, I spend more of my free time now developing, debugging and adding features than I do writing.
I went to church for the second time in years this past Sunday. I am moved by what I hear, but there is a silence when I try to listen for God's voice.
I do nanowrimo every year, and it means setting my family a little less for November. You give them the rest of your life, you're allowed some time off
On the other hand there are more books on my to read list than I'll ever have time for in life. If I left my job and family and lived alone in a library for the rest of my life I might just manage it, but probably only if the rest of humanity stops writing more books I want to read