Maintenant je sais

Okay managed to translate the lyrics from the French, not entirely literally though, just probably what it means. Please help.
It's by Jean Gabin... nice French crooner

"When I was young, the height of 3 apples
I spoke confidently, to be a man
I said, "I know, I know, I know"

It was the first time, it was spring
And when I had my eighteen years
I said "I know, there you go, this time, I know"

And now, the days, they return to me
I look at the earth, where I took a hundred steps
And I still don't know how it turns

For around 25 years old I knew it all
love, the roses, the high life
Damn right, love had made everything turn
Fortunately all my lovers
had not eaten all my bread
in the prime of my life
Still I learnt
What did I learn? It's held in three-quarter time words

The day when someone loves you
It's beautiful
I cannot put it better
It's beautiful
Me, who's in the autumn of my life

One forgets so many nights of sadness
but never a morning of tenderness
All my youth, I wanted to say
"I know."

Only, the more I sought the less I knew
As 60 blows strike on the clock
I'm still at the window, looking, asking myself
Now, I know, but one never knows!

Life, love, friends, money, roses
One never knows the noise nor the colour of anything
This is all I know, but that I know well."