Isn't slavery illegal? AND since i'm so mature does it mean I'm an old soul or something?

I mean if slaverly is illegal than why do some jackassed adults seem to think parents own us? I mean if they own us until we're 18 and we're supposedly not in the state of mind to think for ourselves than isnt that sorta like slavery in its own way? I mean I'm only 12 and I've been abused verbally and physically but I'm also pretty damn popular and smart and I'm way more mature than any of the 14 or 13 year olds in our school. What in the world is THAT supposed to mean? Am I an old soul or am I just too awesome to be dumb? Haha not to sound like a smart *** but I really am wondering what ya'll think about it.