Yep, no surprises there.
Some people get the idea that if they manage to produce a single cohesive thought, that they are thenn the smartest person who ever lived.

It was similiar to the Downing study from way, way back, which showed just how many were so dumb, that they did not realise how dumb they were.

Ignorance breeds certainty.

Actually this disorder really becomes apparent to anyone who interviews prospective employees and is then able to follow the employees' work history for a period of time.

It was the ones that uhmed and arhed about certain technical questions and infact asked questions back for clarification that were ALWAYS the best choice, ...they knew more, learned more easily and had greater flexibility in problem solving. The cocksure, I can do anything are the ones that end up having a warrenty rate 10 and 20 times the norm.

Eg, I was probably 10% slower in my work than most of my equally qualified colleges...but my warrenty/call back rate was in the order of .3% (3 jobs per 1000) most of the others were around 30 per 1000 so it balanced out numerically but not economically....but the ones that thought they were the best were mostly in the triple figures, and one of the most delusional (would tell you he was the best) was between 200-250 per 1000. Lost a lot of respect for my then boss because of the character.

My part time job is to clean and set up a local cafe in the morning for the morning trade. They have the same person put the tables and chairs away every Sunday afternoon (I can always tell when this person has had to work a random evening shift).

This person shows incredible creativity in putting the tables and chairs away. It varies from week to week but has not ever been in anyway logical nor helpful to the person that has to put them all back out again in the morning. Hilariously, I'm sure this person is putting considerable thought into and feeling a sense of achievement.

Yes mate, good call. I'll pay that.