See if you can ask around for his name, but don't come across as too desperate when you finally do come across this man of mystery on the Instagram. I'm not saying there's anything wrong with having a crush on someone you don't even know, but in my mind, you should've sprung into action the moment you met, asked his name, got to know him, got his Instagram username, and who knows? You could've taken things from there. Sorry to disappoint, but you may have already missed out. Nevertheless, don't give up hope. I would've long before now, but you could still have a fighting chance.