First, I would like to study two cases.
Billie Jo is an average high school girl. Ever since middle school, her friends and her had always been in the school's chorus. Moving into her upperclassman years, she realizes that having taken chorus for so many years, she has missed out on other electives that she never bothered to even look into. When she brings the idea up to her friends, they shoot it down, and Billie Jo is expected to show up after the summer sitting in the exact same 1st soprano seat.
And then there is Michael. Michael gives the impression that he hates the mainstream. His whole persona is to be so far away from pop culture that he seems to be living in another era. He swears that he listened to Dubstep in 2008, and then when Skrillex came out it "all went down hill". He wears mismatched socks under his shoes that have different color laces, and wears large poindexter glasses that have no prescription because he has perfect vision.
These are two very different cases, but they have problems that are rooted in the same source: lack of originality and thinking for oneself. There is no real happy ending here. Billie Jo does what she is expected to do, and graduates with top honors in the music department, but then goes to college hating singing, and spends money on an introductory course in what she never knew she had a talent for: psychology, a class her high school offered for free. Michael goes the rest of his high school years unhappy with the way he is, because what he doesn't know about himself is that he is a natural born leader, and thus he comes to school every week with a different style because everyone starts to mimic him.
There is however a solution to both of these issues. Here it is: Find what you really enjoy doing and do it. Especially now, high schoolers. High schoolers have so much opportunity to learn what they enjoy. High schools offer classes in everything from history to music theory to psychology to computer science to languages. If you take an elective and don't like it or get tired of it, drop it. That means it is not a passion for you. By all means, move on.
Also, don't go against the crowd for the sake of going against the crowd. That's stupid. By no means am I condoning anyone to fall into a conformist pit of following those who are considered by all outside sources to be "better than you". But here is a hint: If many people like it, it may actually be good. Sure, society has a knack for exploiting the mess out of trends until you can't stomach hearing Adele sing "Set Fire to the Rain" not even one more time before you commit yourself to the happy house. But don't oppose it from the beginning because it is accepted. It is alright to like things others like. Its okay to not like things other like.