Answer: Very often. But I try to draw some conclusions from this, correct them, and move on.
In principle, every next step should be based on the correction of the previous one. A correction is possible if you appreciate your mistakes.
This is why it is said: “For there is not a righteous man on earth that does good and sins not.” That is, our every step should consist of: mistake-fix, mistake-fix. This is how we advance.
Therefore, I often tell my students: “I check whether it is worth doing so or not. Let’s think together, maybe it is too difficult for you. Maybe we will take a step back.”
I do not hide this because it is necessary in order to teach people how to relate correctly to moving forward. Moreover, it can only happen through mistakes. The work on the mistakes is what’s most important.
From the Kabbalah Lesson in Russian 7/1/18