Here's a Thought

It jumps and hops
It falls and plops
Has love and hate
It's curved but straight
It can be small
It can be large
It comes with no charge
And can't be bought
It's in all
It's in some
It's Clear as day
It's Dark as night
It's Mysterious
As curious
It can be black and white
It can be colorfully tight
What is my riddle as I bid you good night?