Why it may not always be right to design as smooth a journey as possible.
This idea seems counter-intuitive at first, but makes perfect sense on further reflection.
…people who had an issue with a service that was later resolved gave a better rating to it than people who didn’t have any.
It reminds me of a story (which I now cannot find) about someone who annually camped out for nights on end to get tickets for a particular event. One year, this person’s dedication was rewarded with free tickets. This gift offended the person. They derived their utility from the effort they were putting in (or perhaps in showing that effort to other people). The value was in the struggle.