Confession time!
1. As a very new student I was starting the Tomahawk when I glanced across at the instructor and noticed he was smiling slightly. Thinking he was having a nice day, I gave a taxi call and opened the throttle....a bit more and she should start to roll....just a bit more...then the penny dropped.
I shut down and got out to undo the tie-downs, then noticed the row of smiling faces in the aero club window. The instructor didn't say anything, and he didn't need to, it was the best lesson I could have had!!
2. Years later, having recently completed my homebuilt Fisher 'Classic' 2 seat biplane, I was experimenting with the prop pitch. This involved dismantling the blades from the hub and re-assembling with different pitch blocks. Having carefully re-torqued everything, I started up and attempted to taxi out. She seemed reluctant to roll on the grass, so just a bit more throttle...and we slowly reversed! The hub was able to be used with left or right handed blades, and I'd assembled it @rse about!
In my defense, I also had a microlight which used the same type of prop as a pusher, so I was used to seeing it that way around. Very embarrassing though.
Why is it that these things always have an audience, but perfect landings are never noticed?
The moral of the story? There's always time for a good pre-flight. "Better late in this world than early in the next".