Any Gay, Lesbian, or Straight people ever thought they were bi, but later, learned they were not?

i always thought i was straight. i had a friend that i was always very protective of. i thought it was fine to care so strongly about her but the last time she slept over we got drunk and made out. sparks flew everywhere and i never had that experience with a girl until then. i am madly in love with her. i just cant see myself with a guy.