While I see what your getting at to a sense, I dont entirely agree with the logic and reasoning you used to get there. What you said is akin to saying you're lying to yourself if you say you dont like grapefruit, only oranges, because from certain distances and in certain scenarios they look different and may be mistaken for each other.
People are largely similar, and there is much give and take between genders. Common social standards are what are usually the defining factor for what is discinctly male or female (ala long head hair and zero body hair being female, short head hair and hairy being male), but of course, like any gradient, there is cross over. Some people may align with their gender physically, and some may not. What it comes down to is personal preference. Someone who is male, might possess traits which another male finds attractive, and this is just where physiology, and preferences might intersect.
However, I do agree with you that there are many more people whom hold some kind of physical and emotional attraction to people of their own sex (ie. are bisexual to some degree) than most would have you believe. The desire to fit into the mold created by previous and present generations of social normality is a much stronger force than the one to be true to yourself for most. Unless ignoring that part of yourself is ignoring what the individual considers a substantial part of themself (which could mean anything, as I said, its what the individual considers substantial, what is substantial to some, might not be to others) most will live that part of their life as it fits the mold. What this also means however, is that there are people who simply are not attracted to people of the opposite sex, just as there are those who are not attracted to people of their own. Some people like ONLY oranges, some ONLY grapefruit. Most PREFER one, but will try both at some point in their life.
Beauty is in the eye of the beholder as they say, but whether or not you communicate those feelings of beauty and lust and such is a product of far more environmental factors.
So I think anyways