When somebody corrects you for one little typo.........?

I see myself as a perfectionist and I'm always using correct grammar and spelling and I NEVER Use slang unlike other people of my age. I don't feel the need to correct's people's spelling in statuses and I think it's a bit out of hand to keep doing it. . Not sure why she wants to waste her time doing it either. I only correct people if i'm talking to them on facebook chat or on Msn or something like that and usually, i'm close to that person.