What do you do about ideas you think of when you're not at a computer? Or when you're at a computer that doesn't have access to the network you usually store notes on?

I pull out my phone and use Beorg, which syncs with my Dropbox. The next time I'm at my computer, the notes are right there in Emacs.

press a single key combination, of course! but in vim!

That's the best feature of vim, it works even when you're away from the computer!