Do you ever kick yourself later on for not approaching someone you find interesting?

Since I am now staying with my mom she sent me up to McDonald's earlier to grab us lunch. I went inside to order at the kiosk and when I was waiting for the order I spotted this woman at a booth having lunch and I thought she was very attractive and she seemed interesting. I kept glancing over but was too afraid to approach. I noticed halloween themed tattoos and some pins on her bag so I thought oh cool she's like me. Many hours later I keep thinking about her and am annoyed that I wasn't brave enough to say hi.