How (Grammar & Spelling) Nazis have fun

If you've ever corrected a person's grammar or spelling, it's possible you've been labeled a "Grammar Nazi"or a "Spelling Nazi". If you've ever corrected the same person's errors more than once, it's not only possible, it's likely.
I've been called that when I've offered unsolicited help to people. I'm not sure I understand why. It wasn't in a public forum or presented in such a way as to cause embarrassment. If someone were attempting to balance their checking account and clearly placing decimals in the wrong spots, a person who points that out is not going to be called a Nazi. For some reason, people expect to be cut slack when it comes to being sloppy with the words they choose to express themselves.
Well regardless (not irregardless), I don't like being called a Nazi (it's a word that's thrown around too easily anyway) so I don't offer unsolicited help anymore. I also have a long memory when it comes to who called me one when they come to me, with an entirely different tone. Such was the case at work the other day, when a co-worker who got aggravated when I tried to explain that making a sign that says "DO NOT LOOSE THESE KEYS" doesn't make sense suddenly wanted my help when composing a text message to his sweetie:
CO-WORKER: Hey, how do you spell 'cologne'?
ME: Hmm, use it in a sentence?
Co-WORKER: Like 'I really like the way your cologne smells' or 'your cologne drives me crazy'?
ME: Oh, like 'that is some sweet-smelling cologne' or 'I can't get enough of your cologne'?
CO-WORKER: Yes, exactly.
ME: C-O-L-O-N.
CO-WORKER: Okay, thanks.
ME: You are more than welcome.
I'm no Nazi. A dick, maybe, but not a Nazi.