Oh, I 100% agree that there would be some kind of exponential falloff in which notes I go back to.
I just, again, for me personally, gain a lot of value from writing the notes even that I never go back to revisit.
So for me personally, the metric is interesting, like I said, but doesn't capture "how useful" a note is, because I have most of my utility outside of that use case.
1. I have it committed to memory.
2. I never needed it.
I have no way to discern whether either (1) or (2) will happen as far into the future as you care to specify; so it's mostly a moot point. In any case, I will sometimes just do random walks through my notes, wikipedia style, and find a lot of value in it.
I just, again, for me personally, gain a lot of value from writing the notes even that I never go back to revisit.
So for me personally, the metric is interesting, like I said, but doesn't capture "how useful" a note is, because I have most of my utility outside of that use case.