Age of Another Reason

How few hours I need all to myself,
I only take as much to keep my health
So I stay strong and sit up straight;
Brush my teeth and exfoliate,
Thus my wants becomes my shoulds,
Adolescence ends in parenthood
Like piston-work in my puzzled soul,
I change from candle-wick to steaming coal . . .
Shall this rhyme set to solemn bell?
Now I serve, yet I serve — now I swell —