Through my time in school and other experiences, I've come across several people (including myself) who have felt the need to be someone they are not to fit in with others they are surrounded by. All too often, we just want to be a part of a group. We'd do anything to feel included, and unfortunately, we lose touch with who we are and who we truly want to be in the process.
I am not denying how disheartening it is to feel like you don't fit in with a group. It sucks. Sometimes it can make a person feel insecure, and that is where becoming someone you're not often begins. You lie, you do things you would never even think of doing. You create a façade for yourself; suddenly, you are exactly what you think you've always wanted. You can fit in now, but how worth it is it?
Maybe it is all worth it. Maybe you would rather give up facets of who you are than learn to love being different. Maybe having several friends who don't know who you really are (and don't care either) is better to you than having a small group who loves and accepts you. Maybe this is all okay for you, but I know now that I could never live a life where I am essentially deprived of who I am to feel as if I belong.
Sometimes, people are cruel. They can be mean for no reason and they will go out of their way to make sure you know you are different. But it isn't fair to yourself to change for people who base their livelihood around popularity and exclusivity.
Be yourself. Keep your sense of humor, talk about your likes and dislikes, and never mask your quirks. Be friends with people who want to get to know you and love you for you. Don't settle for being friends with people who want you to take the picture instead of be in it with them; don't settle for people who clearly do not care about you.
"To be yourself in a world that is constantly trying to make you something else is the greatest accomplishment" - Ralph Waldo Emerson. There is no one else in this world exactly like you; own that fact and surround yourself with people who appreciate you.