"I take it when I remember"

This is the fade, and it's the version that most readers will recognise even if they've never made a decision to stop anything. The tablet was every morning. Then a morning went wrong and it wasn't. Then it was most mornings, and then it was when you noticed the packet, and now taking it feels like an act of memory rather than a routine.

The scale of this is worth knowing, because it's easy to think you're unusually bad at it. The Cochrane review of interventions to improve adherence opens with the finding that people prescribed a medicine to take themselves typically take only about half the prescribed doses. Half. That's the average across conditions, across countries, across decades of studies. The reader who takes it four days in seven is doing about what everyone does. That's not comfort, exactly. It's a reason to stop treating the fade as a character flaw and start treating it as what it is, which is a design problem.

The design problem is that a daily tablet has no hook. It isn't attached to anything, it produces no feeling when taken and none when missed, and it competes with a morning that's full of things that do. Memory was never going to carry it, and the studies say memory doesn't. What does work, so far as anything does, is worth knowing too. A review of 771 trials of ways to improve adherence found modest effects overall, and found that the interventions that worked best were the ones built on habit and routine rather than on information and persuasion. Knowing more about your tablet doesn't get it taken. Having a fixed place for it in a fixed minute of the day does, more often.

So the fade isn't cured by resolving to remember. It's cured by taking remembering out of it, and chapter 21 is the method. For now, the thing to see is that "when I remember" is a system, and it's the system most people are running, and it delivers about half.