I have a presentation next week and one of my slides will address "bit rot". The concept is familiar enough and I think many who doubted this years ago have probably all been hit with a first-hand case of this data disease by now.

I've got some good examples of this going on in EPROM data (cartridge prototypes) but I have never personally experienced a CD with bit rot. I know I've seen or heard people in this community talk about it before.

Do you have any specific examples of this happen, and was there an obvious culprit (heat, humidity, excessive light, etc) that caused a once working disc to go bad without ever having been used in the interim?