Is it normal to forget what people look like?

So this doesn't happen a lot of the time, but I occasionally forget what people's faces look like. For instance, last year there was this guy at school that I used to like, and over the weekend I'd always completely forget what his face looked like. I didn't have any trouble recognizing him when I saw him again, but I was always frustrated because I could never remember him. (I can remember his face now though) I'd even be able to see, for instance, a picture of him in our schools yearbook but I STILL couldn't keep it in my head. If I concentrated really hard though I could get this vague, fuzzy image. This is just an example though; it's happened with a couple of other people. Actually right now I'm a little upset because there's this guy I like that I met last week at this summer camp thing that was a week long and I won't be able to see him again until next year but I've already forgotten what he looks like. Actually, even when I was THERE I couldn't always remember. Also, there was this one time where I couldn't even picture my own face, and instead I kept picturing this random girl's face that I'd just met and known for like an hour, instead of me. Is this normal?