They all know who Rufio is.
a Teenager
a Sword fighter
a Pirate Hater
a Loyal Friend
a Lost Boy
But beyond that , there's not much else to say about him.
He always follows orders. He doesn't question the actions or decisions that Peter makes. All the Boys know that he will always protect them and help them with whatever they ask.
Everyone who knows of Neverland knows that the longer you stay there, the more you forget. But despite all forgetfulness, there still seems to be something he remembers from life on The Mainland. It plagues him in his dreams and is manifested in his attitude when fighting and towards pirates.
If he's so loyal to these boys and will do anything for them, what could he possibly be hiding that he can't share?