I write short notes on every movie a see on the big screen. This is mainly to keep track of what I've seen, and to remind myself about the movies later.
Looking at the collection of comments, however, reveals a trend that I find rather interesting. The movies I like tend to get quite short entries (see the 2005's entry for the Incredibles for example), while the longest entries tend to be for movies I did not enjoy (see 2003's comments on the Reign of Fire, for example). While there are numerous short entries for movies I didn't enjoy, there are very few long entries about movies I did enjoy.
I'm not quite sure what this reveals about me, but it does suggest that I find it easier to analyze where something didn't work than what aspects did work.
While my behaviour is unlikely to change, it is an interesting observation.