Ever think about the vastly different lives you could have lived?

I visited my home city the other week and met someone who was kind and chivalrous. I sensed connection between us, but I'm married, so nothing happened. But it gave me a strange feeling for the first time that I haven't been able to shake off. What if I hadn't married the first guy who was the most practical choice? What if I had moved back to my home city and met someone else? What would my life look like now? He's from another country, so I started imagining myself learning his language/culture, and visiting his country. A completely different life from what I've lived so far.

I don't regret where I am now, but I do feel sad that there's so much life I haven't experienced and won't ever be able to for the rest of my life. How do I realistically get that experience from where I am now? I feel I've been chasing maturity and stability faster than anyone else my age, and I've missed out on just exploring life. Anyone have a remedy?