Some of it is mental, but ultimately it does get recorded into a record-keeping system of some sort. It's too hard to always pull out the record-keeping system and keep things in it. However, when the record keeping system looks like it's running on empty, I tend to brain dump into it.

Just tell yourself to have a one-track mind and make your list and record keeping system your life. Never deviate, and just always do little steps always. Every big picture should always be made of thousands of little pictures.