In a world of endlessly approaching deadlines and pressure for always better results, who has time to do a retrospective? It turns out, successful teams do. Undertaking the necessary discipline it takes to develop the habit of this part of the Agile process does take effort but the end results are well worth it.
For a lot of teams that try, these end of sprint meetings can quickly turn into personal anecdote sessions and become completely based on 'gut feel' that is just a painful step that does not feel like it accomplishes anything valuable.