When I first started mtn bike riding I rode with a friend who called out objects in the path...roots, rocks, turns, etc. Once I was working really hard to make it up a pretty steep hill - head down and really crankin' - and she called out duck. I thought she was telling me there was a duck in the middle of the trail (there are ducks in the area - just not where we were). I quickly figured out what she meant AFTER my forehead smacked right into a low hanging tree branch. Thank goodness for helmets...you don't have to crash for them to help you! NOW THAT WAS DUMB!
As we must account for every idle word, so must we account for every idle silence." ~Benjamin Franklin