During the spring of my sophomore year, I had the biggest crush on a girl--a lovely dance student with a great laugh, and dark hair that smelled like oranges. We started dating, spent all our time together, and marveled at how "right" everything seemed. I even considered moving into her apartment. It all felt terribly grown-up and exciting and significant. Clearly, I was a lesbian.
Three intense months later, I fell madly in love with a handsome boy line cook from Jersey City--just around the time my girlfriend told her parents in Tennessee about her newfound homosexuality, and her serious girlfriend (um, me).
Her parents freaked. She was devastated. Of course, we had an awful breakup. And to this day, there is a lesbian ballet instructor in Nashville who believes I am the antichrist.
The moral of my story, ladies? Avoid any grand proclamations about your sexual identity at a time when final exams and Jäger shots are still a routine part of your life. Experimentation is healthy, and experimenting with other girls is totally fine. You're allowed to be sexually adventurous and fickle. But if you draw premature conclusions about sex and love and things that actually matter, then you're just being a dumb, impulsive kid (not to mention an insult to authentic lesbians).
Go ahead! Make out with your roommate in the dorms! Do the two-finger tango with that hottie in American Poets of the 20th Century! Just remember that it's okay to try being a lesbian, then realize it's not for you... just like it's okay to try it and realize it's absolutely for you. What's NOT okay, however, is rushing into it--coming out to everyone you know, marching in the Pride parade, listening to a lot of Ani DiFranco, loudly insisting on how here 'n' queer you are--before you really know what team you're playing for.
To prevent cringing at yourself a few years later, or worse, hurting someone you really care about, don't let your fingers write a check your tongue can't cash. Dabbling in some girl-on-girl action is normal; not being honest about the fact that you're only dabbling is just being an asshole.