Loving their cool hardness in our hands. (14)
Check out this sensory detail. Doesn't it just stick with you? No wonder the speaker remembers it to this day.
The cold smell of potato mould, the squelch and slapOf soggy peat, the curt cuts of an edgeThrough living roots awaken in my head. (25-27)
Again, the speaker has very vivid and specific memories about potato digging that stay with him into the present. Our guess is that in his future career, he's going to be doing a lot of writing about potatoes.
But I've no spade to follow men like them. (28)
So it turns out our speaker is quite different from the other men in his family. Why does that matter so much?