Here's a handy jools flowchart for whenever you feel masochistic...
1. It's my opinion, and it's always right.
2. Your opinion is invalid. See 1.
3. I'm allowed to exaggerate and blow things way out of proportion regardless of the validity of my argument or yours. See 2.
4. I'm an expert on anything that I type, including things I really don't know about, and definitely things that you know more about. See 3.
5. I will never concede a point regardless of the fact that I may be completely wrong/round the bend/in a mood/missed Emmerdale. See 1.