If you use emacs then org-mode is a natural suggestion. Personally I have two git repositories that store org-mode files; one for a work-journal, and one for p

If you use emacs then org-mode is a natural suggestion. Personally I have two git repositories that store org-mode files; one for a work-journal, and one for personal files ("DIARY.org", "BIRTHDAYS.org", "REFERENCE.org", etc). Random reminders/ad-hoc tasks I use google's todo-list, because it is easy to work with on a mobile. I just have a couple of tasks "things to buy" with subtasks for things I need to remember (e.g. "buy bleach") and a couple of scheduled tasks "change toothbrush", "clean windows".