It goes like this: someone estimates how long it should take you to code a piece of software. You know the estimate is unrealistic and that no way you are going to make it. So you would imagine that you would just shrug your shoulders and code at whatever pace you are comfortable, not really considering the deadline at all. The thing is, you will still feel the anguish anyway.
The same point was made in Facts and Fallacies of Software Engineering by Robert L. Glass.
I’ve noticed similar phenomenon in playing poker and while doing other estimates, like trying to set up the timetable for writing my thesis. One approach, though not practical for software development, was presented in Elements of Poker by Tommy Angelo. The idea is that you don’t want to have goals, but rather targets. In context of poker this essential means: aim to play every hand as well as possible, but don’t have for example monthly goals to earn set amount of money or play set amount of hours. Tommy proposes that having goals isn’t productive due to missing goal having much larger negative impact than vice versa.
All this is highly amusing, until it happens to you. As with all emotions, it is very difficult to ignore the anguish of missing unrealistic deadlines. Like making a new year vow that this year I’ll drop 30 pounds/quit smoking/etc. and missing year after year. You know the surrealism of it all when making the vow, but still you feel bummed when you fail.