If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
I occasionally get the feeling that I had an important thought just now/a few minutes ago. More often than not, I can remember it by thinking about it for a few seconds.
Well that is the usual case of it, retrace my steps or think about something else for a few seconds, but in the described cases I can't for the life of me figure it out again.