Yeah, I was thinking of old 8-bit computers that did the same ignore-after-second-char thing. Most people didn't bother typing the extra characters though because 1) those characters took up valuable memory and 2) if you accidentally put a keyword in the middle of your longer name, the tokeniser would see it and assume it was a keyword.

e.g. Calling your variable FORGET seemed like a good idea until you got a syntax error because FOR and GET are both keywords. FO it is, then. Or just F.

COLOR was cursed too; OR is usually a keyword, even if COLOR itself isn't. British English COLOUR might save you here, but you're still losing those four extra bytes.