It's nice to be able to just kick back and enjoy.
you can't kick back...you just signed up!
Then I guess I better kick it up a notch.
Whatever you wish, neighbor
I get no kick from champagne --
Mere alcohol doesn't thrill me at all,
So tell me why should it be true,
That I get a kick out of you? Cole Porter, "I Get A Kick Out of You"
I was taught that "kick" or to get your kicks comes from a dancing background. When people danced they kicked up there heels. So shortened "Kicks" became a term for fun.
Is that more like the answer you were looking for?