How we cite our quotes: (Line)
Quote #1
My father worked with a horse plough, (1)
Whether you like it or not, your parents shape your identity in one way or another (even if it's just genetically). The opening of the poem might be a set up for the son to compare himself to his father in some way.
Quote #2
I stumbled in his hob-nailed wake,
Fell sometimes on his polished sod; (13-14)
So much of finding yourself can be a rocky road. As the son struggles to keep up with his dad, he looses his footing along the way, both literally (in the field) and probably figuratively, too. He has to find something besides farming to pursue, because he's not really good at it.
Quote #3
I wanted to grow up and plough,
To close one eye, stiffen my arm. (17-18)
As a kid, the speaker thought he could shape his identity based on his father's. He thought his father was pretty great, so why not grow up to be just like him? One problem: he inherited just about zero of the farming skills that his dad had. Time for plan B.