I have a bunch of single-author projects that I wrote myself that I no longer have a deep understanding of. None are near as large as your references. Fabri

I have a bunch of single-author projects that I wrote myself that I no longer have a deep understanding of. None are near as large as your references. Fabrice Bellard is obviously a superhuman, but I expect even he relies on re-analyzing code he previously wrote and has subsequently forgot. This doesn't take him long because he knows his own conventions and proclivities. But I'm confident he doesn't "deeply understand" the entire code base. He has a shallow understanding of the entire code base. He has a deep understanding of crucial parts of it. And he has the ability to quickly re-establish a deep understanding of any piece.