What am I?

You can hide me or introduce me to a few. But if you show me the world, I will leave you. What am I?

related riddles

I like to eat food but water kills me what am I

Rich need me poor have me if you breath me you die

I cannot speak but I have great knowledge, I’m not a tree but I have leaves. I have hinges but I am neither a door nor a window. What am I?