Answer:
I have all the knowledge you have. But I am so small that I can fit into your hands. What am I?
He has married many women, but has never been married. Who is he?
I am one small little piece of paper yet sometimes hold lots of value. I am all you need to get in to big events but will cost you. I am an important part of travel. And if lost you're not coming.
The letter S is added to pluralise most words in the English language. eg. Letter to Letters Word to Words and Language to Languages. But I am a word that is pluralised with the addition of the letter C.
When I am caught, I am thrown away. When I escape, you itch all day. What am I?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.