watching your back, preppy clothes

[NoClue]

Hi .
This is the lyrics of Avril Lavigne's Complicated song.

..
You become
Somebody else
Round everyone else
Watchin your back
Like you can't relax
..
Take off all your preppy clothes
..

There are 3 things I don't understand
1. Should it be "you become somebody else LIKE everyone else"?
2. What does she mean by "watching your back"?
3. I found Preppy in my dictionary, a person who goes to a preparatory school. But what is a preparatory school? What clothes do they wear?

 

[Song Sprite]

the word "Round" in the third line should be written 'round. It's an abbreviated form of the word 'around', which in this context means 'in the presence of'.

'Watching someone's back' means protecting someone by guarding the places they can't see. Like if two people are being attacked, they will often stand back-to-back.

Preppy clothes are popular clothes. A 'prep' does not necessarily mean someone who goes to a preparatory school, although that is where the stereotype orginated. Now it is a stereotype at most highschools. Try looking in a dictionary of slang for a more accurate definition.

In my school, the main classes of people were preps, jocks, geeks, and goths.

If you are interested in learning more, try www.wikipedia.com for explanations of those - search for:
prep (slang)
jock (subculture)
geek
nerd
goth subculture

 

[NoClue]

Thank you. I still didn't get the term "in the presence of". My friend said the meaning of that is "You become somebody just chasing after girls". And hence what the "around" word is for. What do you think?

So the guy "watches his back" because he is insecure at his new state?
And preppy clothes mean pop culture clothes?