I've heard other successful people do this to, not in writing but just mentally going through the day and assessing how good/bad the events of the day went. It

I've heard other successful people do this to, not in writing but just mentally going through the day and assessing how good/bad the events of the day went. It gives closure and makes it easier to drop them from the conscious mind. This was also what the methodology in Getting Things Done was mostly about.