I've found that the same works for me when I put forth the tiny bit of time and effort to actually do it.

Just a quick note somewhere (phone is easy-enough, or for a long time I carried a waterproof Field Notes notebook with a Fisher Space Pen and that worked a bit better), to be reviewed later.

Maybe that review happens an hour from now. Maybe it happens in a week, or a month. Or maybe all of these. Refreshers are good.

I don't even have to write much, if anything, about the person; the mere act of taking down the names usually helps a ton with my ability to recall the context later.

If I can remember when and where I took that note (which I can often do very easily), then the rest of the details fill themselves in quite nicely.

(I don't erase the notes, so as to let them remain useful to me later. I don't care if that creeps anyone out; my intentions are pure and the problem I'm trying to solve is very real. Its creep-value is really no worse than the contact lists that I've transferred between cell phones, pocket computers, and now pocket supercomputers for nearly a quarter of a century.)