So an important part of learning how to meditate is learning how to fall. They say that when you start learning Aikido, the first thing they teach is how to fall without hurting yourself. The purpose is that it makes you less and less afraid to fall, less and less damaged, of course, by the fall, and also less likely to fall, more willing to take chances.
So the trick when you meditate is learning how to bring the mind back with a minimum amount of recrimination, a minimum amount of self-criticism, with just the simple observation, “I haven’t come here to think about next week’s schedule or last night’s fiascoes or whatever. I’m here to focus on the breath.” Simply leave those other things and come back. Learn how to do it without tying your mind up in knots..."
Thanissaro Bhikkhu from "How to Fall"
Full talk here: