Though for some people it only becomes clear that they are gay or transgender later in life, many teens, and even young children, are very certain of their sexual orientation or gender identity.
As one teen says,
"My parents say that I am too young to know that I am gay but I have known since I was in 3rd or 4th grade. But the thing is, how old were they when they knew they liked the opposite gender?"
It is also very common for a teen to question their sexual orientation. Some teens experiment with same, or opposite gender, relationships as they work to discover and develop their identity. Sometimes this experimentation is a sign of sexual orientation, sometimes it isn't.
Some people assume that teens who think they are gay are just confused by "hormones," but as the website Scarleteen points out:
"During adolescence, we do tend to be what's called "less selective" about sexual partners due to a couple things: not just a bunch of hormones flying around, but also because that's a time when we are feeling all of this out, starting to figure all of it out. That can mean attraction to people we might not be as attracted to during another time of life, it may mean choosing sexual partners less cautiously, it can mean having less barriers to sexual relationships. But that's the case for many young people of all sexual orientations, so I'd not put too much stock in the idea that your hormones have the power to make you feel things you wouldn't otherwise be feeling. Most of our interpersonal desires and longings are about our hearts and minds, not about estrogen or testosterone. Plus, you'll have those hormones once you're out of adolescence, too."
So just as many teens are very aware that they are straight, some are also very aware that they aren't.