Strange feelings

I don't know how to feel, honestly, I've been in love with a guy for 4 years, I still have those beautiful memories that we had when we were a couple, now we're complete strangers and I remember that I talked to him a month ago but I got really nervous and I didn't know how to continue the conversation LOLOLOLOL I still feel that need to talk to him but do you think it's a good idea? He doesn't remember me at all now, I'm a stranger