Answer:
Two in a whole and four in a pair. Six in a trio you see. Eight's a quartet but what you must get is the name that fits just one of me.
I can be simple or I can be complex. I can be found in this riddle or in everyday life. I can be shapes or even colors.
I only exist when you are here. Where you never were I can never be.
The more you take, the more you leave behind. What are they?
I have all the knowledge you have. But I am so small that I can fit into your hands. What am I?
I flow from the Homerβs mouth when he sees doughnuts.