It’s not completely known what causes someone to be lesbian, gay, straight, or bisexual, but your sexual orientation probably started at a very young age. This doesn’t mean that you had sexual feelings, just that you had feelings about who you were attracted to. As you get older these feelings get stronger and shape your sexual identity.

Sometimes sexual orientation changes over time. And sometimes it stays the same throughout your life. But sexual orientation isn’t a choice, and can’t be changed by therapy, treatment, or pressure from family or friends. You also can’t “turn” a person gay. For example, a girl who plays with toys traditionally made for boys isn’t going to become a lesbian because of that.

Sexual orientation can feel incredibly simple — you’re a girl who’s always liked both guys and girls and you identify as bisexual — or it can feel way more complex. It may take several years to understand your sexual orientation or come out. Some people call themselves questioning, which means they aren’t sure about their sexual orientation or gender identity. This is common — especially for teens.