Distant stars are therefore depicted on the long-exposed plate which never could be seen by naked eye. The mind is such a sensitive plate, and the power of impression depends upon the length of the exposure. Every student needs to cultivate the power of concentrating his mind on themes, of going after and recovering lost and incomplete trains of thought, and of holding and burying truth in the mind until it takes deep root.” A brief glance at your past life will reveal to you the truth of all this.