Here's one for alfagal
NEW MYSTERY
We are three
Sitting snuggly in the wisdom organ
Arranged from top to bottom
There is nothing much in front of us
But there is a big ball shaped triangularly
At the back of us
There are fluids in between us
Without us, life is definitely not in the dictionary
We can make you sleep for long hours, days and months
If we are hit hard enough
What are we? 
MYSTERY
SOLVED
