Some observations

Inspired by catching a snippet of conversation in the hallway, "...how can someone take algebra if they don't know how to do fractions?"

One: People are, as a rule, remarkably good at forgetting anything that they decide is unimportant.

Two: When it comes to academic topics, people are remarkably bad at correctly determining what is unimportant.

Three: Observation #2 probably applies to most topics, really.