Why do some people that say they have common sense constantly display that they have little to no sense?

Two things are said about people, but rarely true if the person says it about himself:

1) They have common sense

2) They have class

I like the pic of the cat, pointless, but I like it anyway lol. The actual reason why ppl who say they have common sense yet display that they don't, I have no idea. From my experience tho, I would venture a guess that the reason they do is to convince ppl to believe in that they have common sense. I use my parents as examples, they do have some common sense, but most of the time they don't and it's not just displaying it with actions, it's with words too. They constantly want me to believe that they are right and have common sense, but then compare a sleeping medical issue to working graveyards. Well, common sense would say that a medical issue is not the same as working graveyards, not even close to the same. I mean, finger food is not really made out of fingers. Anybody with common sense would know that, however my parents, through their common sense, would say that working graveyards and sleeping a few hours after work and getting a steady flow of oxygen to your brain would give you just as much of a restful sleep as having sleep apnea and getting no oxygen to your brain off and on during those few hours that you sleep. Again, common sense doesn't make the comparison, but they do. If you want an example of their actions showing no common sense, one time someone accessed porn on their computer, they knew it was my brother, because he had done it several times before, yet they said they knew for a fact it was me when they had no facts. I wasn't living at their house and wasn't even coming over to visit, but since it happened three days before I came over, it automatically was me because I was there, despite the fact that common sense said it was my brother since he had done it the last three times that they had accused me and because I wasn't there. Well, there's two examples. Again, the best answer I have is that I believe they do it to convince others that they are smart and have common sense, no other reason, cause they try to convince me that all the time, then I point out that there never is common sense with them, that they are stupid and that gets them defensive and pissed off lol, but most of the time, the truth hurts.

People have a hard time finding flaws in themselves, but no problem finding them in others. Here is a picture of a cat.

People can say what they like. Its up to you if you take it on board or not.

You are only accountable for your own actions,( unless The Hive Mind tells you otherwise! )