The others usually exclude Sam from any adult-like activities (such as drinking or watching Orphan Black). To which Sam doesn't understand because she's 18 like most of them. One day they finally told her why, it was because they wanted her to be the baby, as that's how they all saw her. She was the youngest, so she had to be protected. Sam didn't really mind, though. In fact, she was kind of happy that her friends cared so much about her.
