This time around with my knitting, I am keeping track of my pattern by these marks.
I had to google what to call them. At first I tried "hash marks," and that could qualify, but it also means marks on a sports field and the "pound sign" or "number symbol" # (also known as a "hashtag" by people savvy enough to tweet). But the more precise term seemed to be "tally marks."
Since I need to knit 4 rows then purl 1, I can make an upright mark after each knitted row, then slash across after I purl a row.
The flaw would be if I forget to make the mark after each row, and that is a real possibility. However, this is still likely to be more accurate than my unassisted memory.
There's also the issue of my handwriting. You might notice in the 3rd group, the 3rd line has a squiggle next to it. Was that just a sloppy stroke on the 3rd mark? Or was it a 4th mark that I made tinily and messily because I was sleepy? I asked myself that this evening, and decided to go with the sloppy 3rd stroke hypothesis. I knit a row and the purled a row. I had actually gotten up and gone on to another activity before I remembered to go back and make the purl slash.
So not a flawless system, just less flawed than no system at all.