Why do people act like this around me?(long, sorry)?

I'm just going to start with saying that I'm 13 and in seventh grade. I care about how I look and take the best care of my body that I can, but I don't wear makeup. I don't have too many clothes because my family is going through a rough time, but my mom and dad did save up to get me the latest iPhone model, the nicest thing I have. I try to mix and match my outfits as much as possible so it looks like I have more clothes than I do. I love theater and am rarely alone because I like to surround myself with friends. I love to read and do it almost every free second I have, and I have very good grades. I'm by no means the average teenage girl trying to impress boys. I think I act pretty genuine and recently got the part of a supporting lead in our school play! However, I've been noticing something. Whenever I talk to someone I don't know too well, they try to act cool, or popular. If I watch them with their friends, they act way different. Just today, I saw a girl act cool and goofy and then later say to me, "oh my god, I can't even!" Other phrases obviously different people have used with me:
"I literally love your hair so much, girl!"
"Oh my god, that boy is so hot!"
"Ew. No way."
Why do people think I'm like this? How do I get rid of it?

It's called "people are people and you are by no means special or the cause of how people act."

I'm so sorry kids and hormons act like idiots around people who are honest and pretty to them you have to keep safe and learn to deal with idiots who will try to impress you or try to pursue you to change or be with them.

They are either making fun of you based upon your style, of identifying you as cool and believe cool people talk like that. Either way I think you are better off ignoring it.