It reminds me of writing an objective examination in high school and when you're done with the questions you're certain of, and you just do some random selections and luck could shine on you and you get up to 70% from your rough prediction.
I can relate to that, literally passed examination once with random answers on subject I knew little about.
On topic, I'd say you got really lucky with your predictions and luck might not favor each time, there being no real money involved also played it's part because it's like a beginner trader who does well in demo trading but gets bad results when trading with real money.
Have you ever placed a bet by just doing random guesses on the outcome of the game?
No, and I have no plans to do so.