I was once a good kid

I've been thinking a lot lately...mostly cuz that's all I could do. I've been grounded and I haven't been able to go much of anywhere. so as I was saying, I've been thinking and I've realized how much I've changed in the last year. I've gone from being a typical American teenager to something like this. I was a "good" kid, I did my homework, stayed in school. then everything changed. I was hanging out with the smokers and the drugies, I skipped school, I even ran away. I've been thinking about how I've changed and why. I'm not saying that it's a bad thing that I've changed I'm just wanting to know why it happens. maybe I'm just growing up...what do you think?