in Thoreau’s Journal:

Now that there is an interregnum in the blossoming of the flowers, so is there in the singing of the birds….With a certain wariness, but not without a slight shudder at the danger oftentimes, I perceive how near I had come to admitting into my mind the details of some trivial affair, as a case at court, and I am astonished to observe how willing men are to lumber their minds with such rubbish, to permit idle rumors, tales, incidents, even of an insignificant kind, to intrude upon what should be the sacred ground of the thoughts…

It is so hard to forget what is less than useless to remember.