Topics like this are so hard to discuss because, I mean, I know what I want---my orientation is geared in a certain direction perhaps due to genes but definitely due to all of the experiences that have made up my childhood up until now---but how am I to understand the person next to me and label them as gay/straight/bi when I don't even know 0.00001% of the experiences they have had? Also if they may not even understand/know what they want, how am I supposed to?

There are a lot of thing such as sexual and physical abuse/neglect/etc. that can really screw with someone's thinking.