I was once sitting around the regulars table at the bar discussing education. On this particular night, half of the people at the table were scientists, which was not unusual given where I lived. The topic was on how schools often only test whether people can perform the skill, but not whether they understand what they are doing. As an example, multiplication was brought up.

Well, the one scientist with a masters degree suddenly asked "What do you mean in regards to the multiplication example?". At first we thought he was not being serious. After explaining multiplication, he was happy to now know what it was and had not realized his entire life he did not know this.