Write it down.

I worked for many years, for a particularly forgetful / reckless / dishonest boss, who made so many £u(4-ups that I began writing down every single instruction and always had, to one side on my desk, a pile of A4 sheets of paper perhaps 20cm / 8" high with perhaps 30 instructions on each.  She used to be flabbergasted that I could find in seconds an errant instruction from months earlier, but could not tell what I'd had for lunch the previous day.

@charles-rockett, LOL! I know what I had for lunch yesterday! I can tell you what it was. It was...ummm...errr...I wrote it down somewhere. Now, where did I put that note?

@jkuvakas Lol.