I remember expressing something similar when growing up and my friends asked why I always downplayed my abilities and accomplishments. I guess I felt the need to surprise myself as well as others who I found were always expecting more from me.
This may partly explain the tendency towards hyperbole expressed by certain fanatical supporters of especially gloomy predictions. The Y2K had their fair share of exagerators and one wonders if January 2000 was a particularly happy month for them. The doomsday scenarios of today are no exception: James Lovelock, who conceived the Gaia hypothesis, says that we’ve already passed the point of no return with regard to global warming. Matt Savinar maintains a particularly scary website explaining why technology is not a panacea for peak oil, while James Howard Kunstler speculates on the disastrous consequences on an oil addicted civilization. This doesn’t mean that they’re necessarily wrong, but the believers of their extreme outlook will be happy even if the lesser of two disasters comes to pass.
Professor Schwartz’s quote shouldn’t be taken out of context. Planning one’s life based on the lowest expectation of every possibility will inevitably lead to lost opportunity and regret. His larger point is that having too much choice has the downside of higher expectations and increased chance of disappointment. It is a case of the Goldilocks Principle that I can spin to my advantage next time anyone criticises my past career choices: The Caribbean had too few options for career growth, the US had way too many, and the UK was just right.
NB. Google TechTalks has for a much longer version of the Professor Schwartz lecture.