Answer:
Before Google, we actually had to physically look things up in this building full of knowledge.
Sometimes imaginary and sometimes real, sometimes they are the closest and dearest person outside the family. Who are they?
You fill it and it empties, A metaphor for plenty, Depending on what half you see, It's either full or empty
He died for people's entertainment.
Without this, H2O would just be 2O
Cycle Cycle Cycle.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?