Id Like To Slap The Guy Who Invented

Nulls in database strings

Neckties

Wikis

Case-sensitivity in file names

Case-insensitivity in programming languages

Case-sensitivity in programming languages

Differences in human preferences

The marketers who create strange, confusing, and inconsistent version numbers/letters. "Do you want Foo X-Whammo Foo Super, Foo Semi-Whammo, or Foo Whammo X-Minus-One? We have a deal on Foo X-Enterprise Whammo and Foo X-Enterprise Whammo Extended. If you get it before Foo Doublewhammo comes out, you can get Foo Whammo Enterprise Express for the same price as the next version of Foo Whammo Zeron-Z with Gesture G5 and G-VI."