I used to play a lot of tennis. The city of Springfield, Massachusetts ran a tennis lessons program for a while in the summers; I believe we heard about it because one of my older brother's friend was an instructor (his name was Scott, he worked washing dishes at Friendly's, and I believe he drove a yellow Ford Mustang Cobra, although where it would have come from I don't know). Fortunately, summer programs cater to the parents of three bickering sons, and Mom always used to play tennis, so I guess tennis seemed like a good bet. I played off and on for many years, with Dad, the neighborhood kids, or my younger brother.
Down on Cape Cod there's a condominium development called Sea Pines, and they have tennis courts, with combination padlocks on them. The development is quite large and a lot of the units just get rented out to tourists most of the year, so if you just go to the tennis courts and wait, someone will come along and happily tell you the combination. So Ben and I played there a lot. They also had a wall with a net-high white line, if there wasn't anyone around to play with.
One day I was there, possibly alone, and there was this girl there, about my age--with her own coach, some Australian guy. She was largely unsmiling, as so many die-hard competitors seem to be, but she lacked an opponent, and I asked if she wanted to play. Her coach asked me if I was pretty good--he wanted to make sure she had a challenge and that I wouldn't be wasting her time. Well. I was okay, but I've never been better than intermediate. Still, I thought I could give her a little run for her money, so I said I was pretty good, and we set to.
She did kick my ass, but it took her a little while, and boy, was she pissed. Eventually she muttered (bear in mind she was losing to a half-assed unstyled stranger, in front of her coach) that she was getting all screwed up because my forehand had backspin on it.
I don't know if you know anything about tennis, but forehands don't usually have backspin on them. The typical forehand stroke is very powerful, with topspin to make it go faster when the ball hits the ground. However, I sliced downward on my forehand, making it a less powerful stroke with backspin that caused the ball to land close to the net and drop dead in place once it got there. She was far and away a better player than me; she just had a really hard time adapting to something completely unexpected, that she'd never even heard of before.
I hope she smiles more now.
As a footnote, in high school I eventually learned how to control my forehand, so that I can now choose whether I want topspin or backspin, how much and in what direction (I can actually put sidespin on the ball sometimes--man, if you ever want to see an opponent get really confused...). I've been bitten by the "what the hell is this?" problem myself: playing racquetball in college, I learned to serve the ball so that it would land an inch or so in the air, where the wall and floor meet...the way racquetball works, that wall is to the left of the receiving player, so it's a backhand for most (right-handed) people, and they can't get to it and they lose the point. Well, one day I played a skilled left-hander and got my ass kicked on my serves a few times before I got the hang of what to do with him (put the ball to his backhand).
Always the unexpected.