Volunteers were requested at work to give 30 minutes of instruction to student nurses about what our department does. It came down to two of us, and the other person, a male about my age, challenged me to Paper, Rock Scissors, best two of three, loser has to teach. It caught me by surprise and I accepted.
He beat me in two moves. I wondered if I had been snookered, so I looked it up. I played exactly as novice males often do, and he had the correct answer both times, so I suspect he preys upon hapless, naive RPS players often, and knows the simple strategy.
Neophyte males tend to play "rock" on their first move, neophyte females tend to play "scissors." Next, inexperienced players tend to play against the strategy that just beat them. I played "rock," he beat that with "paper." I played "paper," he beat that with scissors. I am going to bet he wins with that paper-scissors strategy a fair bit, challenging people who are unsuspecting.
I don't know why I chose what I chose. The explanations seemed implausible to me. But there it is. So now you know: catch people by surprise and beat them at RPS.