The moment you try to restrain the mind in meditation, you see how powerful it is. The very fact that i cannot hold on to one thought for any length of time, for a minute, or two minutes, or five minutes, shows that the mind has impurities. Unless you work at it, it will remain the same. It'll trouble you continuously. And also it's impossible to remain at peace. I understand with all the veranta and sanka and mindfulness meditation, all of that is fine,. but when the mind kicks up a storm, its difficult to remain the witness and difficult not to suffer.