I hate "I could of done more." Obviously, it sounds like that, but it is spelled "I could have done more."
Also, when someone says "I could care less," they are conveying exactly the opposite of what they mean. It is "I couldn't care less," as in the amount of my caring is zero, I don't care. But saying "I could care less" means the amount of caring is greater than zero, I do care.
Finally, one must use a space after a comma or period. Sentences like this one,which ignore this rule,make the speaker(or poster)look stupid.Very stupid.
Yes! That one drives me nuts! As does a space between the last word in a sentence and a question mark or exclamation point ! No watt eye mean ?
That was originally an ironic usage, a trivialization of the subject, as in, "I suppose there are things that would interest me less but it is all so uninteresting that I can't be bothered to recall what they are."