Lately I’ve been thinking about inventory.

Ranchers talk about it all the time. On any given day, they keep or sell or buy weaned calves, bred heifers, replacement heifers, dry cows, old cows, steers, bulls, semen and embryos. Some cows calve in the very early spring, others later. Some replacements are AI’ed, others aren’t. Some heifers are sold bred, others not. Some cows are fed in this pasture, others aren’t.

When pressed for details about when and why they stock or sell animals or when and why they breed or feed them as they do, ranchers talk about markets and prices, yes, but also about more ephemeral things: weather, vacations, wedding anniversaries or ‘how Dad did it.’ In other words, sometimes their economic decisions seem rational, sometimes random.

At first, I didn’t get this. It’s your business, I’d think, why don’t you have a fixed idea of the best time to do the best procedure or make the best sale for the best outcome? But when I consider my own inventory style – the entire stock of my household, the materials, components and work in progress – it’s also decidedly unsystematic. It’s also surprisingly effective.

For example, the other day I turned up at the Costco Tire Center with a persistently low pressure tire. While the car was being worked on, I dove into the store with a sudden fever: this is my moment to grocery shop. I hadn’t known it was my moment 5 minutes before, but I knew it keenly then. I bought salmon: fresh for that night, smoked for upcoming parties and frozen for an unplanned weeknight dinner sometime in the future. I bought cheese: cottage for smoothies, baby individually-wrapped mozzarellas for kids’ lunches and a large brick of cheddar for grating. I bought almonds, raw for making granola and salted single serve packages for snacking. I bought flour to make bread, but also actual bread and crackers. I bought canned tomatoes to make sauces, but also a jar of premade Marinara sauce. I did this all without thinking too much at all.

If somebody had stopped me then and there at 10 a.m. Wednesday morning to ask me the kind of questions I regularly ask my ranchers about why, precisely, I was buying jasmine rice, basmati rice, rice crackers, rice noodles, cellophane packets of rice ramen, as well as rice pho in disposable bowls instead of, say, swimming laps, sweeping the kitchen floor, writing a story or walking the dog and why I didn’t think to use the time to exchange the too-small lined pants I bought my husband for Christmas, given that the mall was right there and the 30-day return window was closing, I couldn’t account for myself. Why, indeed? Why do we do anything – or many things – when and how we do them?

And yet, if pressed – as I no doubt press my ranchers – I could look deeper and see that my decisions have to do with opportunity costs, maximizing resources and offsetting risk. Yes, I randomly found myself at Costco at that time on that day, but my actual purchasing decisions were fairly rational, informed – albeit unconsciously – by my deep knowledge of the dining habits of the household I was stocking.

I guess I understand more about ranching than I thought.