I would guess that it was more likely due to the pick-and-choose nature of most courses. When I take a class, the material that is actively tested is usually o

I would guess that it was more likely due to the pick-and-choose nature of most courses. When I take a class, the material that is actively tested is usually only the general concepts and only the ones the professor deems important. Wikipedia is designed for you to be able to get a general idea about specific topics, where a text book is designed to include in-depth and comprehensive knowledge.