Most ideas come to me while I'm nowhere near a computer, so it's impossible to note them all down.
Even this one -- the realization of the illusion that many people have, including me, that it's possible to note down all our ideas in a ["zettelkasten"][797984e3] that will contain the history of all our insights -- is only noted later, with great distress since I forgot the other thoughts that lead to it and now am wasting time mentioning these unknowns forever lost.