Or when someone looks at me in general

That's what happens when I look in the mirror

Even when they look in my general direction.

Or when one of your favorite actors is in a picture looking directly at you.

Sometimes when I am talking with someone I don't find attractive I find I am more charming and my personality comes through more since I feel more comfortable around them. Because of this people I am not attracted to often respond like they think I am into them. So whenever an attractive person is nice and acting comfortable with me I can't help but think "crap. I must not look attractive to them and that's why they're being so charming"

I suddenly forget how to walk

That's I hold eye contact and wink. ha jk I'm not that confident.

It makes me feel great when an attractive guy looks at me. Even better is when I'm serving an attractive customer and they have the cutest smile that they give when they say thank you (let's add that almost everyone at my Tim Hortons location each has a crush on a customer. We know and will inform them when they come in)