I wish that my teachers growing up had more often told me to "Mess around" and "guess."
I took this photo at Scratch Day 2013 at MIT. It was posted on a wall where participants were asked to write down what they did when they got stuck in Scratch. If you are the kid who wrote this, thank you.
As both a student and teacher, I have noticed that willingness to follow the advice given above is often directly correlated with success in programming. I find that once students are over the feeling that they have to get it right the first time, they start to experiment and "mess around" until they discover both the "answer" and the logic behind it.