It's why I answered "don't know" on the OP poll. They aren't the right questions, IMO. Normal isn't a useful way to characterize human sexual orientation. It's common, present in all cultures and for all of recorded history at least, even in societies where being gay and getting caught brings a death sentence.
The relevant question to me is whether or not being gay is a choice, or whether it's determined by factors outside the control of the person, and I don't think there is any doubt (for all purposes that matter) that our sexual orientation is NOT a choice.
The second question is whether a person can change their sexual orientation. And there is simply no evidence they can.
Obviously in a population of hundreds of millions in the U.S., billions worldwide, there could be rare exceptions. But these exceedingly rare exceptionsaren't useful to consider for purposes of decision making. So the only useful assumption is that no one chooses their orientation, and when that orientation is set, it can't be changed. Enough societal pressure, or religious pressure, can change behavior, but not orientation. So if you find out your cousin is gay, assume he's always been gay and nothing anyone can do will change it. If you're a woman, and meet a guy who says he used to be gay, assume he is still gay, will never change, and act accordingly. If you want to criminalize gay behavior, and justify it because you believe it's a choice, and offenders can simply choose to be straight, you're wrong, and will make criminals out of people who had no role in their being gay.