They [mistakes] occur on average once every ten words... If people say an average of 15,000 words each day, that's about 1,500 verbal blunders a day. Next time you say something, listen to yourself carefully. You st-st-stutter; you forget the words, you swotch the sounds (and when you type, you reverse the lttres - and prhps omt thm too). The bulk of these go unnoticed or brushed aside, but they're all fascinating, as much as for why they're ignored as why they're noticed.The next time you are teaching public speaking or teaching students to write, remember that the absense of error should never be an objective. This means that every time you make a deduction in a student's grade for their mistakes, you are really teaching them that mistakes are something that should never happen - if they just tried hard enough - if they just prepared more - if they just studied more - if they just cared more - mistakes would never happen.
To sell life as an exercise in mistake-avoidance is not only impractical but it is wholly unhelpful and untruthful.
Mistakes are a part of our life - and we are better for it. This is why I proudly hang a sign outside of my classroom door that reads: Mistakes are our Friends.