Have you ever regret about something your whole life?

My biggest in life... when I was a know-it-all teenager, I had an opportunity to go with my parents to see my ill grandmother. I chose not to, probably to do something with my friends. I knew my grandmother's health was failing, but like so many teens I was way dumber than I thought and assumed I'd have another chance to see her. As you can guess, I imagine, I didn't get another chance. She passed away about a week later. 💔