Agreed. Unfortunately, I've met many (primarily school) teachers who have been less than impressive. Some can't hold down an adult conversation. One informed us all (at a friend's baby shower) that you get vitamin C from the sun and suggested the mom-to-be take exorbitant amounts of Calcium, because you can't take too much. Knowing full-well this was wrong and dangerous, I quickly interupted with Please see your doctor for dietary supplements & advice.
There are lots of great teachers, but there are lots of duds too.

@scurry Oh wow. I can not believe these people are teaching, in my training we had to pass basic Maths, English, Science and Social Ed questions. If you could not pass them you had to do an extra unit to understand them. The pass mark was 100% I nearly failed the Maths one when I failed to notice that the mark on the page (there were lots of them) was in fact a decimal point. The lecturer told me I had one wrong and in shock I said, "No I don't." he showed it to me and said what about the decimal point, I then put the point in my answer and got it right took me ten minutes to complete the test.