We had a lovely session of shamata practice this morning and I read this quote from Trungpa’s The Path of Individual Liberation p 232

If you don't have a good relationship with yourself, you cannot understand the dharma, and your body and mind will not be properly coordinated. The practice of meditation helps you to coordinate your body and your mind. You realize that your mind can be directed to a particular effort, that your mind works. Through shamatha you are able to raise your mind to an adult level. Your mind does not jump all over the place whenever you try to do something. In this samsaric world, most of you have grown up physically, but psychologically you are very young. You can't concentrate. You can't eat even one good meal properly because your mind is constantly jumping all over the place. The basic message of shamatha practice is that your mind could be as adult as your body.