Slightly off-topic, but Allen also makes the point that you need to trust your system to remind you in time to get your task done—just writing it down doesn’t do any good to “get it off your mind”. If don’t trust your system to actually remind you to do it when the time comes, it will still be distracting your attention in the meantime. You have to check your task list as frequently as necessary to make sure you don’t forget anything (it is a matter of your unconscious thoughts trusting the system, as soon as you slip, you’ll have to start rebuilding your trust).
Slightly off-topic, but Allen also makes the point that you need to trust your system to remind you in time to get your task done—just writing it down doesn’t do any good to “get it off your mind”. If don’t trust your system to actually remind you to do it when the time comes, it will still be distracting your attention in the meantime. You have to check your task list as frequently as necessary to make sure you don’t forget anything (it is a matter of your unconscious thoughts trusting the system, as soon as you slip, you’ll have to start rebuilding your trust).