Answer:
The more of me you take, the more I appear behind you. What am I?
Adored by few, feared and hated by many. Mistress of the entire universal reason, master in the art of numbers. Some may have solved many of my mysteries, but there are still many of them to find. What am I?
I may seem real but it always turns out I was never there in the first place... you only see me during a certain resting stage.
I am not a toy though many use me for pleasure. I have a butt but I cannot poo.
What do you call a pig that is no fun to be around?
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.