Daniel Kahneman and Dale Miller explained in 1986 why it is more annoying to be five minutes late at the airport and just miss your flight, than when you arrive thirty minutes late and miss your flight completely. The difference lies in how easily people can think about the alternative scenario. If you're five minutes late, you can easily imagine what you could have done differently to make your flight just in time, then when your delay has risen to thirty minutes. The easier you can think of alternative scenarios ("If only I had created an extra backup"), the stronger the emotional reaction ("How awful the research data is lost!").

By starting the article starts with the phrase "What should have been one of the best days of her life ", you can just see the alternative scenario in which the PhD student is celebrating with champagne in her hand. This make you feel even worse about the actual scenario where she spend "nightly hours at the police station".

For the same reason, it is more annoying to flunk an exam with a 5, then to completely fail an exam with a 2. When friends call you to ask if you want to go and have a beer, while you have an exam the next day, I'd suggest you think about it carefully.

An exam not passed by a tiny bit is especially annoying if you can easily imagine how you would have passed the exam, if only you had not gone to the pub the night before.