For, after all, how do we know that two and two make four? Or that the force of gravity works? Or that the past is unchangeable? If both the past and the external world exist only in the mind, and if the mind itself is controllable what then?
When we think of the past it’s the beautiful things we pick out. We want to believe it was all like that.
When the mind once allows a doubt to gain entrance, the value of deeds performed grow less, their character changes, we forget the past and dread the future.
We must not confuse the present with the past. With regard to the past, no further action is possible.