Ideas and insights are fleeting. Once they disappear from your mind, it feels like they might be gone forever.
Fine! You’ll think of more. Don’t trouble yourself with trying to capture each and every idea that barrels through the door of your head. That’s a form of paralyzing perfectionism. If you’re writing and forget a sentence that you were about to write, don’t spend hours trying to remember it. Keep writing, and more good sentences will come to you.