Notes are different from essays. They aren’t polished arguments; they are impressions caught in transit.
When you underline a sentence in an old paperback, you are leaving a small breadcrumb for your future self.
“We read to know that we are not alone.”
Keep a small pocket notebook. Write down the title of the song playing in the bakery, the turn of phrase an old friend used, or the color of the dusk sky over the hills.