Answer:
You do this into someone's ear when you want to be discreet.
Before Google, we actually had to physically look things up in this building full of knowledge.
This is the drinkable phase of matter
If you have me, you want to tell me. If you tell me, you don't have me.
What object has keys that open no locks, space but no room, and you can enter but not go in?
What never gets any wetter no matter how hard it rains?