I have had plenty of times where I was convinced I was right and was proven wrong afterwards.
One of my painfullest memories was the time we did a Simpsons quiz among friends. Having only seen a few episodes, I was sure that the person who shot mister Burns was Smithers (for in one episode they showed an alternative ending to the mystery episode) and people tried to convince me otherwise (with the true gunman) and I didn't give in.
Later, when I saw the true episode, I felt like a total idiot and I still whince whenever I look back at it. (granted, I was only 12 at the time)
As to teachers and laughing, I once made a teacher burst out in laughter when I asked about heartbeats.
For in physics class we were thaught of measurements of time. The issue of the timespan between heartbeats came up. My gues was less then a tenth of a second or so, whereas the answer was 1 second (or, yeah, I don't know really)
To which I asked if it was between boom-boom and boom-boom, or boom and oom (because each beat, to me, consists of several sub-beats.
My latest memorable embarrassment of ignorance was when a foreigner asked for directions and I explained that if he took a big street, he would end up on a large 'plain' (I refered to a part of the city, like a city square/market place)
I was kind of convinced that I was using the proper terminology, but my GF laughed at me flat out, saying how I directed him towards a giant aeroplane, and even defending myself by explaining that plain also means a large open space, she pointed out that a plain is something like a field, in nature.
I felt incredibly stupid and hurt at that. (certainly I was due to give a lecture in English that Friday, kind of crushed all my confidence)
