What about really branching off and thinking along the lines of Love , lust, sleep, hiccups, flu, hate, menstruation etc as a force of nature!
i know am a force to be reckoned with at certain times of the month!lol (teen age girl reaching womanhood, the taboo but inevitability of a monthly bleed, moods etc)
The destructive nature of love/lust, the addiction of it all?
The fight a child has to postpone sleep, the need for sleep, dreams?
Masturbation, sex, the natural force a baby has while in the womb...the skin stretching on the mother, the pressure on her bladder etc
sorry am rambling now lol just got excited by all the possibilities :)