If you assume that people remember the solutions to every problem they've ever encountered, I would not like to use the kind of user interface you would create!

If you assume that people remember the solutions to every problem they've ever encountered, I would not like to use the kind of user interface you would create! Here's the Wikipedia entry on the subject, which describes how 12am/12pm is actually a common confusion. https://en.wikipedia.org/wiki/12-hour_clock#Confusion_at_noon_and_midnight https://en.wikipedia.org/wiki/12-hour_clock#Confusion_at_noo... Incidentally, 99.9% is going to be a bad guess for almost any survey answer because of the "lizard people effect" (4% of US adults say that the country is controlled by lizard people, 7% are not sure).