I have one more comment about the previous MythBusters episode where they compared two cars crashing into each other at 50 mph vs. one car crashing into a wall at 100 mph. At the end of the episode, Jamie reflected on the experiment. He said something like (regarding how he incorrectly thought one car at 100 mph was the same as 2 at 50 mph):
What a great attitude. I think this is something many students miss out on. Which is better, taking a class where you know everything and don't even need to study - or a class that confuses you and makes you feel like you are going to pass out? Well, the first class doesn't do anything for you. If you already know it, you can't learn it.
If I go back to my favorite learning-exercise analogy, if you work out and don't even break a sweat - did you work out?