I just use a big text file where I keep all notes and todos (do use a [] as well), separate dates in a structured way with most recent date at top. Typically edit it in emacs. It just keeps getting bigger and bigger, but it’s nice to have a single text file that I can search.
A lot of dynamic Econ models have some condition where my choice today depends on an expectation of the future. Like how much I choose to eat today depends in part on my best prediction of how much I’ll eat tomorrow. For aggregate decisions, getting better predictions should improve welfare.