A tip for those who might buy in to the "write tasks down in a place you trust" from the "Getting things done"-system, but who feel the todo-list becomes overwhelming, I highly recommend the tool Todoist.
https://todoist.com/
It is a todo-list, where the default view only shows tasks that are due TODAY. You can also create views (aka. filters), like a "WORK" view where you only see work tasks etc.
This means you are much less likely to be overwhelmed by the amount of tasks on your list.
So if I need to remember to pay a certain invoice next week, I will make myself a task for next week - and since I trust the system, that is now cleared from my mind - and will re-appear next week - when I need to action it. If I put it in the calendar and ot NOT action it - it is lost. If it is in Todoist, it does not disappear until I say it is done.
It means I end most days with an empty todo-list.
Todoist took my using a todo-list from not really working - to a very integrated and trusted part of how I do everything.
(I don't have any association with Todoist - I have just been a very happy user for ~4 years. I hope others will benefit as well.)