Use your brain to solve problems and think, not to remember things.
The best state of the brain is one where it’s not holding “gotta do this” in your working memory. It’s not the best tool for remembering things anyway. It’s best to build an external system that you can operate using your brain functioning in its best capacity: abstract thinking and problem solving.
Tiago Forte refers to a practice of “Capture” as an on-going habit. This is very similar to the concept of the Inbox in GTD.