# Four Slots and a Switching Tax
*Excerpted from Chapter 1 of Outsource Your Own Brain by D.E. Lowery, MBA*
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Four. That’s it.
Not four projects. Not four client accounts. Four discrete items: a phone number you’re holding, the opening line of the email you’re composing, the question you still need to answer, the next step in whatever you were building. Fill a fifth slot, and something falls out. The eviction is quiet. You don’t feel it happen. You just discover, mid-task, that the thing you were holding is gone.
## The Tax You Pay Every Time You Switch
Every time you switch between tasks, you pay a tax. The research on attention residue is consistent and uncomfortable. When you move from Task A to Task B, part of your cognitive bandwidth stays stuck on A — the “residue” — and that leftover attention slows you down and degrades the quality of your work on B.
One widely cited estimate puts the cost of a single interrupt at roughly 10–20% of the productive time on the task you were working on.
Every notification you flick to, every “just one quick reply,” every context hop from Slack to email to spreadsheet back to your draft isn’t free. It costs you a measurable slice of the next thing you do.
## Compounding Losses Across a Day
Multiply this across a solo day. You wake up, check email (switch one), open your calendar (switch two), jump into a draft (switch three), get a text from a client (switch four), pivot to your bookkeeping (switch five), and on and on.
If each switch costs you even 10% of the following task’s productive capacity, and you switch forty times in a day — a conservative number for most solopreneurs — you’re not losing 40% of your day to switching. You’re losing 10% *of* the next thing, *of* the next thing, *of* the next thing, compounding quietly across every task.
The cruelest part: people who get interrupted often report working *faster* on the post-interrupt task. They feel productive. They are, in a sense — they’re sprinting. But the same research shows they report higher stress and produce lower-quality output on what follows.
Speed up, quality down, stress up. That’s the signature of a system running over capacity, not a person running out of grit.
## What the Consultants Learn
Consider the consultant juggling a discovery call while mentally rehearsing what she’ll say in the client follow-up email afterward. During the call, she’s holding: the client’s stated problem, her diagnostic question, the next thing she wants to ask, and the shape of the eventual email. That’s her four, all full.
Then the client mentions a budget constraint. She processes it, but to do so she has to let something go. The email structure she was rehearsing gets evicted. When the call ends twenty minutes later, she sits down to write the email and it’s gone — not the idea, just the half-built sentence she was carrying.
She’s not bad at her job. Her working set was simply full.
## The Fix Isn’t Discipline
The legitimate fix for a four-slot register with a switching tax is not to think harder. It’s to externalize: capture the load into a substrate, let the substrate hold the items, let your brain do what brains are actually good at.
Companies have filing systems, ticket trackers, and knowledge bases not because their employees are weak, but because no one can run a business out of their prefrontal cortex. If you’re a company of one, you need the same external architecture, sized to fit.
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*This post is based on Chapter 1 of [Outsource Your Own Brain](https://www.amazon.com/dp/B0HG9NB8PD), available now on Amazon in Kindle ($6.99) and paperback ($17.99).*
