The brain. Some people are born with Male, Female or Fanpop brain. If they are born with a Fanpop brain, then they may feel the need to physically transition into a Fanpopper. They may even use different pronouns, such as...
You can`t even find Fanpop and get on here if the strong sense of Burger King Foot lettuce doesn`t guide you from within, so it`s a given that all people on Fanpop will have that knowledge O.O