"I'd get bored doing one thing"

Two hours on a reconciliation is a bleak prospect. Part of the appeal of juggling is that it breaks the monotony. A bit of this, a bit of that, and the day passes quickly. The fear is that working on one thing at a time means long grey stretches of tedium.

There's an interesting set of experiments on this, though they're about video and not office work. Tam and Inzlicht ran seven studies with more than twelve hundred people. They let people switch freely between videos, or skip around within one, and compared them with people who watched without switching. People switched because they expected it to relieve boredom. It did the opposite. Switching made them more bored and less satisfied, and they paid less attention.

The effect was weaker in some conditions than others, and a video isn't a spreadsheet. But the mechanism they suggest is relevant. Absorption takes time to build, and each switch resets it.

That fits what people describe when they do get a long run at something. The first ten minutes of a task are often the dullest. You're loading it up, nothing is flowing yet, and the pull towards your inbox is strong. Somewhere after that, if you stay, the task starts to carry you. Time passes without your noticing. People who juggle rarely reach that state, because they leave during the dull ten minutes every time. So their experience of single tasks really is boring. They only ever see the dull opening.

I'd separate two kinds of variety. One is variety between stretches. You spend an hour on the report, then half an hour on email, then forty minutes on the reconciliation. That's a varied day, and nothing in this book is against it. The other is variety within a stretch, where you hop between all three every few minutes. The first kind keeps you fresh, and it's the second kind that leaves you with a pile.

Some tasks are dull all the way through, and no amount of staying makes expenses forms absorbing. For those, the case for one at a time is simply that it gets them over with. A dull task done in one twenty-minute stretch is twenty dull minutes. If you spread it across a day in six visits, you start it six times and it's on your mind all day.