19 seems a bit old for a passing phase. And obviously it is NOT a passing phase in every case, since many people go on to be lifelong homosexuals.
Homosexuality is not like cigarettes. Homosexuality is not like the mumps. It's not an addiction nor is it an illness, it's just the way that some people are... and it not only doesn't matter if it's nature vs nurture, it's just none of anyone's business. It's not even someone's parents' business. As my political hero said, "the state has no business in the bedrooms of the nation."
Mark my words, if you are overly interested in the sexuality of another person, you're the one with a serious problem.
Your statement is inherently illogical and makes no sense.
It is obviously a passing phase for those who do not go on to be lifelong homosexuals.
There is a growing body of medical research that shows that the brain is plastic and malleable. Behavior that is persisted in, hardwires the brain to continue in that behavior. The brain is particularly vulnerable this way with respect to high-pleasure activities such as sex and drug use. It is entirely possible for a normal heterosexual adolescent (and heterosexuality is the presumptive hardwiring) to experiment with homosexual activity, or be forcibly experimented upon in a homosexual manner.
For a variety of reasons, such a child could "decide" he or she is homosexual. If the child persists in the behavior, he or she will hardwire the brain to continue in that behavior. The child then stands a real risk of remaining "homosexual" his or her entire life.
But a brain that is malleable one way, is malleable the other way, too. That is the whole point of cognitive therapy in treating OCD. There are many recorded cases of a "homosexual" discovering five or ten years after adopting the lifestyle, that the lifestyle and behavior can be resisted and even reversed. The brain can be rewired.
I have a very close friend who is living proof of this thesis. He has been married now for over 20 years and has two grown children.
Okay, it makes sense. We're essentially saying the same thing. My eyes skipped over a few words in your post.