Don't be too hard on Hope it's a very common complaint that most teachers seem to acquire.
It's less a complaint, and more of a skill, ippy. As a teacher one needs to have the ability to both make correction and do so fairly light-heartedly. Unfortunately, when the same person(s) keep making similar mistakes, the 'light-heartedly' bit becomes increasingly difficult.
On passing their final exams and becoming qualified teachers, a large number of them, suddenly think that they have by coincidence acquired all of the knowledge in the whole of the universe and this happened to them on the same day they qualified.
Interestingly, ippy, one of the things that trainee teachers are told quite regularly is exactly the opposite - 'don't be afraid to admit that one doesn't know the answer to a given question'. The trick is then to turn it into a homework exercise, both for the class and for oneself, so that you do know the answer by the next time you meet the class.
Once one has done that over 40-odd years, you begin to pick up knowledge and information from a surprisingly wide range of areas of study. If, like me, one intersperses teaching with other jobs outside the education world, one gets to understand other aspects of life as well.
I know this post of mine does sound a bit strange ...
No stranger than most of your posts, ippy