This happened to me a couple of years back, and I only recently opened up to my friends about it ( I was way too embarrassed earlier). Anyway:

At the time I'd just finished a class and was heading back to my day job for the rest of the afternoon. I was waiting on a train platform, playing around on my phone, when I noticed this girl walk by who I found kind of cute. Short, blonde hair, blue eyes, you get the idea.

At the time I was working on getting rid of my very severe approach anxiety, so I took a deep breath and strolled over to her before I had time to think about it. I can't remember what I opened with because it was a while ago now.

What I do remember though, is her staring at me blankly without the slightest change of expression on her face. She looked me dead in the eyes for what felt like ages before screaming out for security (who often patrol the platforms where I'm from)

I panicked, did a runner down the stairs and to another platform and jumped on a train just about to leave (It wasn't going where I wanted but I didn't care at the time). I was completely shocked and scared shitless because this has never happened to me before.

Even though it was stressful at the time, I came to the realisation that I didn't die, I didn't lose my job or have anything happen really, all that happened was a girl overreacting because I came up and said hi.