In meditation, as in all arts, there has to be a delicate balance between relaxation and alertness. Once a monk called Shrona was studying meditation with one of Buddha’s closest disciples. He had difficulty finding the right frame of mind. He tried very hard to concentrate, and gave himself a headache. Then he relaxed his mind, but so much that he fell asleep. Finally he appealed to Buddha for help.
Knowing that Shrona had been a famous musician before he became a monk, Buddha asked him: “Weren’t you a vina player when you were a layperson?”
“How did you get the best sound out of your vina? Was it when the strings were very tight or when they were very loose?”
“Neither. When they had just the right tension, neither too taut nor too slack.”
“Well, it’s exactly the same with your mind.”
Why is it tricky? Because it takes a while to figure out whether you are a too tight or too loose person in this particular situation. I'm clearly a too tight person. That means when I meditate, if I feel it's going wrong--I'm doing it right.