You're very right about not needing to experiment to know your sexuality; it was the same for me. I experimented the other way: I did make out with a guy while I was closeted but knew I was gay, just out of curiosity. I felt nothing, then it occurred to me that it might have just been the particular guy I didn't like and I needed a larger sample size, so i made out with another one and still felt nothing. It was all very scientific
, I've never had any sexual experience with guys since