Here, for my own use and possibly yours, is a collection of responses that I often make in internet conversations. (I use “conversation” loosely here.)
Mix-n-match for your own purposes!
Duty calls: https://xkcd.com/386/
I don’t know how to explain to you that you should care about other people: http://www.huffingtonpost.com/entry/i-dont-know-how-to-explain-to-you-that-you-should_us_59519811e4b0f078efd98440
I cannot believe…
Leopards are classic:
And, if all else fails:
Got any good ones to add, Grumpeteers?