in Thoreau’s Journal:

A journal is a record of experiences and growth, not a preserve of things well done or said. I am occasionally reminded of a statement which I have made in conversation and immediately forgotten, which would read much better than what I put in my journal. It is a ripe, dry fruit of long past experience which falls from me easily without giving pain or pleasure. The charm of the journal must consist in a certain greenness, through freshness, and not in maturity. Here I cannot afford to be remembering what I said or did, my scurf cast off, but what I am and aspire to be.