I'm saying they could audit courses instead of 'taking' them if learning was the objective. Of course, 19-year-olds would never audit courses instead of taking them, because they understand that the degree is valuable, and the knowledge is not.

I've looked into auditing courses for free a few times at my local and graduated college, but I could never find any decent information for the process accept for full-time students (which is straight forward). And for the alternative of paying to audit the course, what is the point? It's the same course, may as well get the credits for it. It's the same as not auditing.

Officially, schools need to restrict access to classes for liability and other reasons. As an alum you may be allowed to audit by paying a fee. It should be a lot cheaper than tuition.

Or, since you know the place, you can just drop in and ask the prof if it's ok to sit in. They'll probably say yes and be happy to have you sit in their class (i.e. not demand you enroll and pay the fee; Professors generally aren't big on toeing the line on such rules). This is extremely common.

Many universities and professors allow auditing for free; there's often no process for it because nobody wants to audit.