https://marco.org/2007/09/13/a-good-bug-i-mean-a-really-good
A good bug, I mean a really good, pound-your-head-on-the-desk-for-a-week bug, is exactly like a magic trick in that something impossible appears to be happening. There’s NO WAY the buffer could ever contain that data. That code path CANNOT be reached with those input parameters. You could NEVER get that number as a result of this mathematical function. Bugs thrive on the same human brain deficiencies that earn magicians their living. We are shown something that is apparently impossible - but the reality is that we just don’t have all the information.