Retroactive

I found the book beneath a pile of junk,

the grease-stained pages curling at the edge.

It’s for the engine of that rusted hunk

I hauled away and left behind the hedge.

There’s a diagram on page one-twenty-four,

a heart-shaped valve I never understood.

I see it now, the way it should have swore

to keep the pressure high and gaskets good.

The logic is so simple on the sheet,

a truth I could have used five years ago.

But now the metal’s melted by the heat,

and I am left with facts I shouldn't know.