It takes years to know.

It takes a crane to build a crane.
It takes two floors to make a story.
It takes an egg to make a hen;
It takes a hen to make an egg.
There is no end to what I'm saying...

It takes a thought to make a word.
And it takes some words to make an action.
It takes some work to make it work.
It takes some good to make it hurt;
It takes some bad for satisfaction.

It takes a night to make it dawn,
And it takes a day to make you yawn, brother.
And it takes some old to make you young.
It takes some cold to know the sun:
It takes the one to have the other.

And it takes no time to fall in love,
But it takes you years to know what love is!
It takes some fears to make you trust;
It takes those tears to make it rust.
It takes the dust to have it polished.

It takes some silence to make sound.
It takes a loss before you've found it.
And it takes a road to go nowhere;
It takes a toll to make you care.
It takes a hole to make a mountain.
- Jason Mraz, Life is Wonderful