How should you keep track of what customers want? Don't. Listen, but then
forget what people said. Seriously.
There's no need for a spreadsheet, database, or filing system. The requests that
really matter are the ones you'll hear over and over. After a while, you won't be
able to forget them. Your customers will be your memory. They'll keep
reminding you. They'll show you which things you truly need to worry about.
If there's a request that you keep forgetting, that's a sign that it isn't very
important. The really important stuff doesn't go away.