Is it normal to be afraid that people misinterpet your immaturity?

I'm 20 and sometimes I say really ditzy things, and on top of that I have moments where I act like a total goof, so people sometimes say some really mean things about me like, "She seems kinda slow." or "Shes really slow.". Its really annoying because the people who say it are people who don't even know me, they just catch me in my very immature moments. But I bet if they really knew me, they'd realize I'm not slow at all. And its also usually when I'm nervous, so of course I act kinda weird because its like my first reaction on top of nerves. I sometimes start giggling, and when I feel nervous I say really ridiculous things, or act forgetful, etc. Then people start to think that I'm slow. Its honestly, BULLSHIT!

When I first started at my current job, I was SO NERVOUS that I was making myself come off as a total dumbass! The sad part about it was that nobody really understood, and they kinda made me feel like a piece of shit about it. It was my first week there, and I was making mistakes with the register. I pressed a wrong button, so it never calculated how much change I had to give back. And I don't know if anybody else is like this, but when I get embarrassed I try to say things to kinda clean up the embarrassment. Everything that I was saying seemed like it was just making me look worse. I would say stuff like, "Sorry, I never was really great in math." or I'd giggle(like an airhead!) and say something like, "I'm so sorry, I get confused easily sometimes...", I mean, it was clear that I was a nervous wreck!But people were not nice about it at all. I felt like I was surrounded by a bunch of jerks. And me being a nice person, if I were watching a cashier get all flustered over something like that, I would've said something like, "Listen, its not that big of a deal. Don't get embarrassed about it. Don't worry about it. Its all good." But everybody was talking about me. One guy even got angry at me because I gave him $13 dollars and change back instead of 14. I apologized and said that I would give him the dollar, and he looked at me and said, "This is common sense!".

I can't say its normal for people to mistake immaturity as slowness, but its definitely common among assholes! Don't listen to those people who mistake you as being slow when you know damn well you're not. They can go jump off a cliff and die.

"I mean most of your actions isn't because there is something wrong with you like you are dumb or slow or retarded it's just that you are extremely immature that you fear that it equotes looking like being retarded ,so you hide your immaturity by acting like a grown up ."

You are doing an awful job of that.

Haven't you already posted this?