If I cared less I wouldn't waste so much time over stuff that most readers will probably never notice anyway. (So in this instance I definitely agree with you, Harry, in the sense intended only "I couldn't care less" works for me.)
On the subject of pet peeves and arguing about English, I was recently browsing some discussions on Pain in the English
*. It's an interesting forum - with a Pet Peeves category, if you're interested.
* I was trying to resolve "If I was" vs "If I were" - see the discussion here