This poster made me smile when I saw it on a friend's facebook page. I never considered myself a Grammar Nazi, but I think it's possible that the title is fitting for me.
Unlike many kids, I enjoyed the grammar part of English class. I liked filling out those fill in the blank exercises where you had to choose the proper word. Like your or you're. To this day, it irritates me when I see it used incorrectly. Even on TV news shows!
I thought diagramming sentences was great fun, the longer the sentence the better. Punctuation exercises brought me an easy A. Spelling, which I consider a close relative to or even part of grammar was easy for me, too. This is not bragging, it's just the way it was.
Now that I'm a grown-up, I know that what brought pleasure and something easy to learn for me might have been terribly difficult and boring for others. I understand that because math proved miserable and tough for me.
Nevertheless, writers need to be especially careful to use proper grammar. Only the other day, I read an interview where several editors claimed that one of the biggest turnoffs when reading submissions received from writers was to find the piece rife with grammar and spelling errors. The content would have to be spectacular for them to accept it and correct all the technical mistakes.
Writers today have the benefit of spell check and grammar usage helps. Use them if you know you have a problem with either one. Sure, it adds a little time, but you'll come out the winner in the end if you send a submission to an editor that has no errors in it.
Google keywords like grammar websites to give you any needed assistance. Spend 10 minutes a day with a grammar website. We're never too old to learn. One I found that looked good is a Guide to Grammar and Writing You'll find plenty of others. Same with spelling rules.
I've decided I'm not a true Grammar Nazi because, even though I cringe a bit when I see a major grammatical error, I never correct the speaker or writer. Not that I wouldn't like to, but my mother taught me to be careful of other people's feelings. I did correct my children but that's in the Mother's Handbook--a part of my job as their mom.