it was a wiley cheesecake

The kid I'm dating, D, is from Huntsville, Alabama -- his father was a rocket scientist back in the '60s -- and he's the kind of person who has kept up with his best friends from elementary school on. (This kind of person mystifies me -- I'm terrible at long-distance communication. I feel productive when I keep up with my roommate.) One of these friends of his owns a comic book/video rental/porn store in Huntsville (and also practices law, awesome), so he comes into Atlanta once every few months with a wagonload of merch for collectors' shows. He stays at D's and we usually all go out for dinner, which always strikes all of us as odd because D is such a good and enthusiastic cook.

So the last time his friend was in town, D and I cooked up a three-person feast: duck, chard, mac & cheese, and a raspberry-swirled cheesecake. The duck & chard were perfect as always (D uses Alton Brown's recipe Mighty Duck, which is fatty and bone-gnaw-worthy), the mac & cheese (a recipe from Paula Dean) was overbaked but worth revisiting with fewer eggs and more cheese than called for, and the cheesecake was surprisingly rad -- the graham crumble crust needed something (less butter? More pre-baking? Parchment paper rather than emergency-subbed wax paper? Better-quality graham crackers?), but the filling was cohesive, creamy, and light, just sweet enough, and with just enough acid from the raspberries.

I asked a couple days later for the cheesecake recipe, and D was like, ?___? recipe whaa? This is the difference between cooks (D) and bakers (me): I would've been scribbling everything I was doing on post-it notes or the backs of receipts or y'know my own arm or the cats or whatever was handy so that I could repeat the chemistry experiment later. D is not a baker: he just MADE the thing, with no fussing or worrying about how precisely it happened. Honestly, I have a lot of respect for that. I also dearly hope that we'll be able to reproduce it from collective memory the next time we want cheesecake!

Have you ever made something that you lost the recipe for, or created in a fit of brilliance and promptly forgot how to reproduce afterwards? Did you ever work it out, or is it The Recipe That Got Away?