Don't you mean "grammer"?

As you get older you learn to expect less from people.
I will correct people that I actually know, and if it is apparent that they're just dumb, I'll quit talking to them.
People I'm not friendly with, I assume to be idiot jerkwads, and 1 law away from worm food.

Please tell me you're joking...

I think a much better example, that OP should have used, is the difference between "I helped my uncle Jack off a horse" and "I helped my uncle jack off a horse".

That's what I said. I asked him to add "could of and would of" to his commonly misspelled words. Not the other way around.

"We are all born ignorant, but one must work hard to remain stupid."

Benjamin Franklin

For me its mostly the annoyance of stopping a discussion because someone was a jerk.

If someone is talking and says, "I wish I are a fish, so I could swim around all day" and then someone else says "You wish you were a fish." or some other conversation stopper. Usually I want to punch that person in the face. First for disrepecting the original speaker and secondly, for being a jerk and stopping the conversation.

How can you be so sure? Ever?

I agree 100%. It's scary that in America we're primarily only taught and expected to speak one language, yet somehow everyone does a damn good job at botching the operation.

Your and you're
Their, they're and there
It's and its
To, two and too

These along with many others drive me insane. It isn't hard to write a halfway proper sentence, no one's expecting you to be perfect, but at the very least try to achieve a writing level higher than a fifth grader.

^ I loled. Seriously though poor grammar and puntuation make some thing unbearable to read. I know I make more than my fair share of mistakes too. I often skip entire posts on these forums after the first few words due to them being very hard to read.

Oh look, social elitist. I'm better then you because I can use a comma.

Communication is about delivering a message. You know what is being said, don't be a jerk and make fun of someone because of how it was delivered.

Ya, grammar would be like those idiots that say turrent instead of turret. What the hell is a turrent. There's no n in turret. Freakin idiots. Look it up.

You're right, the problem is, messages are often misinterpreted due to improper grammar and punctuation. A communication delivered with proper grammar and punctuation is more easily understood by the audience. Indeed, this is the reason grammar and punctuation exist.