Code Review, Years Later

I'm reviewing code I wrote a couple of years ago to determine natural keys of raw data sets, in order to do a talk on it at the local SQL Server users' group meeting next week. After an initial reading, I thought that the code worked a certain way (doing breadth-first searches), but it actually works in a hybrid breadth/depth first fashion.

The first thought one might have would be something along the lines of "comment much?", but truthfully, I do, or at least I think I do. The code is found in a SQL Server Central article, explaining much of the background of the problem I was trying to solve, and the code itself has an entire page of comments, and yet I find now that there simply isn't one concise explanation of the resultant design of my algorithm.

There must be a magic number of weeks after code is finished and polished off, when the original intent of the developer is still in his or her brain, but beginning to fade. That is the perfect time to finish commenting the code, because at that time the developer will have to approach the code as an outsider, but still be able to summon those fuzzy thoughts about why something was done a certain way. Does anyone know what that magic number of weeks is?