Let me begin with this: the movies lied to you. You will not spend your senior year in a whirlwind of parties and beautiful, touching moments that will inspire lifelong stories. For most people, school will be harder than it ever has been. You will spend most of it studying. If you're studious and you've always had a lot of schoolwork, it will be like that, but with twice as many AP classes. If you've never been big on the whole "school thing," you'll be working your tail off to make sure you can walk at graduation.
In general, there are two camps of seniors: those who realize that things will never be the same after graduation, so they participate in everything they can, and those who are "too cool for school" and don't go to anything. I encourage you to be in the first. There are endless opportunities to be involved, and there are different clubs, sports and activities to appeal to anyone's interests. I am by no means saying that you should feel bad if you don't attend every volleyball game or art show, but you should find ways to get involved, because those "lasts" are going to mean a lot to you. The last home football game and the last float decorating party will make way for your senior prom and your final day of school more quickly than you can imagine.
Speaking of which, go to prom. The dances themselves are usually kind of lame, but it's your last big shebang with all of your friends. Take lots of pictures--most of us probably won't look so fancy again until our weddings. Take pictures everywhere, even if you're not an Instagram aficionado. You'll want to see them when you miss your friends in college. Looking back, I regret not stopping my friends for more pictures to hang in my dorm.
Your senior year will be incredibly stressful and incredibly short, but it doesn't have to be miserable. I especially want to stress this: it's okay to get excited about things, and it's cool to have fun. Don't worry if others will judge you for liking your school. School spirit is a good thing! My school had a "Nun Out" at a basketball game this year, where at least 20 upperclassmen boys wore nun habits from a past production of "The Sound of Music," chanting that our team is "Second to NUN." This seems like a totally ridiculous idea, but most everyone loved it. Take part in pep rallies. Hug your friends at graduation. Participate in class discussions. Don't squander your time not caring about things.
Be excited for college, but don't forget to appreciate high school. You'll miss it.
Image credit: slgckgc via Flickr Creative Commons