I'm not friendly IRL so I guess I would never have this problem. I'm actually a little afraid of people...yes, I know I'm pathetic! It's just that I was badly ridiculed in school and it left me with emotional scars. But I wish I were friendly. I would love to be like chickwithsticks, cracking jokes at the grocery store!
But anyways, when a guy talks to me, I assume he is just being nice. About a year ago, I had a guy in class who was always talking to me and my friend told me that he was flirting. I didn't really think he was, I thought he was just nice. Turns out he had a crush on me. It was a shocker for me to find out because I really had no idea he was flirting the whole time. He never actually said "hey, I like you!" LOL We are still good friends though. Till this day he had not told me or asked me out. But apparently he did have a crush on me.