I'm not that cool

At work.

French girl: What's going on?
Me: I'm trying to straighten up my posture.
Frenchy: You know you look like an idiot, all stiff and shit. Your ass is sticking out too much too. You know what man? You don't need to have good posture to be cool, you just need to be yourself. Why don't guys just realize that!?
Me: For fucks sake Frenchy! I don't want to be cool, I don't care! I just want to have straight posture so my back doesn't hurt and I can get a smooth energy flow through my body. If I ever become 16 years old again where being cool is important I will head straight to you to get advice since you seem to be the authority on what is cool and what is not. Until then, save it, cause I. Don't. Care.
Frenchy: You don't care about anything.
Me: I care about me.

She's been dropping her opinionated crap on everyone ever since she started. I lost my 'cool', thus proving that I'm not that cool and admitting that I'm selfish.