"I can keep it all in my head"

People who juggle often pride themselves on this. You know where everything stands. The report is at section two, the reconciliation is at row forty, the supplier needs a figure, and Dave needs ringing. You don't need lists or notes. It's all in your head, and you think of that as part of being on top of the job.

The sticky note on your monitor tells a different story. "Ring Dave back??" has two question marks because by the time you wrote it you'd already lost what the call was about. Something had fallen out.

The part of memory that holds what you're working with right now is small. For a long time the accepted figure was about seven items, from a famous paper of the 1950s. The psychologist Cowan reviewed the evidence in 2001 and argued that the real limit is lower, at about three to five. That's when people are prevented from using tricks such as grouping items together or silently repeating them. He's describing laboratory tasks with simple items, and a half-written report isn't a simple item. But the general point holds, and you'll recognise it. You can keep a handful of things actively in mind and no more.

Now count what a juggled morning asks you to hold. There's the thread of the report. There's the state of the reconciliation, and the figure the supplier needs, and Dave. You've also got the form, and the thing your colleague asked about the formula, and a meeting at two that you need to prepare for. That's seven, and each of them has detail inside it.

They don't all fit. Some are being held and the rest are being dropped and picked up again. When you pick one up again you have to reconstruct it, and you sometimes get it wrong. That's how a call gets forgotten and a figure gets transposed.

It also explains some of the tiredness. Chapter 11 described how open tasks intrude on whatever you're doing. Part of what's happening is that you're spending effort all day on keeping things from falling out. It's effort you could be spending on the task in front of you.

I think pride in holding it all is misplaced, and I say so with sympathy, because it usually belongs to conscientious people. A head is for thinking, and it's a poor place to store things. Paper is cheap, it doesn't forget, and it doesn't interrupt you. The people you may have noticed who seem calm under heavy workloads generally don't have bigger memories than you. In my observation they're people who write everything down and then stop thinking about it.

So the practical step is to move the inventory out of your head. Chapter 16 asks you to list the pile each morning, and chapter 17 adds a capture sheet for stray thoughts and a parking note for every task you leave. Each of those takes something you were holding and puts it somewhere safer. I'd expect the relief to come quickly. I'd also expect the one thing you're working on to get your full attention for the first time in a long while.