Well, you see, the three steps are carbon fixation, reduction, and regeneration of RuBP. But in my own shed, the real cycle is planting, tending, and harvesting my potatoes. All that book-knowledge feels far away when I'm watching my beans climb their sticks in the morning sun. The only cycle that matters here is the one that puts food in my children's bowls.

Ah, in my books at the firm, we start with the net profit. Then we add back things like depreciation, and adjust for the changes in working capital—inventory, debtors, creditors. It is like untangling threads on the loom to see the true picture. For me, the real learning came from seeing our own small farm's accounts; our "profit" from selling beans wasn't real cash if Uncle still hadn't paid us from last month.