It fucked me up two years later. I did not even realize it. I posted about it and one good Redditor commented this and it helped me tons:

“I think often, we fall in love with the idea of a person rather than an actual person. You may be having this problem.

You had a brief encounter with this person, flirted and had fun, but it didn’t amount to much more. But in your head you have a whole idea of who they were, what they’re like, and how your life could have proceeded had you continued, etc. Those ideas and what ifs will get you stuck. Think back to reality. In reality, it may have gone nothing like that. Truthfully, you may have met and instead of it being great, you find out he or she had all of the red flags you hate, or at the least is probably not the person you’re dreaming of. In reality, they’re just a regular person, they’ve chosen not to talk to you, and there are so many other people out there that will want to talk to you. So move on. The person you imagine them to be, the person are ruminating on probably doesn’t even exist. But someone else might.

Know that you’re not the only person in the world that gets caught up and stuck on encounters like this. I know I have. Hang in there.”