Proving it

So, let's see. If I go to this website I can receive an education on casual reasoning. What's more... It's free! I'm pretty excited about it myself and can't wait to dive in.

But

Did anyone notice? There is another class listed on the same page. This other class offers the same information, but for a charge.

Huh?

Now, why would I want to pay for the exact same information when I can get it right here for free?
Well, to prove that we learned to others.
We pay to get credit for our effort.

What?
Who said the entire point is learning?