-129 programmers walked into a bar. The barman said "BUFFER_OVERFLOW".

0b10, otherwise known as '2', is indeed the magic number. I'm sure I don't need to tell you that powers of two are very important to computers. I recently helped someone upgrade their memory (using my 'zero insertion force' hammer, of course). It's hard to explain to someone with no background in mathematics why 2Gb is 2,096,064Kb as far as Windows Explorer is concerned. To be honest, I'm not sure I know either.

Powers of two are important, and (2^x) - 1 is also significant. For example, (2^16) - 1 is now of particular significance to Excel users. Apparently, 65535 is the same as 100,000 (for specific values of 65535 of course).

To be fair, a bona fide calculation error in a program like Excel is pretty unusual these days. My favourite error of this kind was in the standard calculator in Windows 3.1 or Windows for Workgroups 3.11. If you put in the sum 3.11 - 3.1 the answer came up as 0.00 - hence the 'joke' that the difference between Windows 3.1 and 3.11 was nothing. Those were the days...

My admittedly rather tenuous point is that it is very useful when diagnosing and emergent problem in a computer-based system if you know how they are built. Just a small flag wave for computer science.