I like to think I have a decent grasp of the English language. I can use both formal and informal speech, appropriately changing my modes and styles for different situations. This is why I hate it when people tell me how to speak.
Somebody rebuked me for saying "me and Stephen" about a certain situation. I was not writing an essay, I was not speaking to the Queen, I was not giving a Nobel Prize acceptance speech (only one of which I have done: guess which), therefore formal language was not required. I am full aware of the difference between subjective pronouns and objective pronouns and can utilise them both effectively. So, in short, if you correct me I will think you are patronising me. And being patronised is something that I take great umbrage with.
Some people have certain bugbears with usages of words. 'Random', 'epic', 'fail' are to name a few. I like this words and use them frequently. Just because people use different words than you doesn't make it wrong. One individual announced their dislike for the use of the word 'times' (for instance, when someone says "good times", or "bad times"). I think they have Dickens to blame for that.
Do not oppress me with me with your semantic elitism. If the vernacular was good enough for Chaucer, it is good enough for me.