Well, sometimes you can sell them. I'm having trouble unloading my GeForce 8600 on Craigslist for $20, which I thought was a pretty low price. And nobody has been interested in my 24-inch TV, even at a nominal $15.

EDIT: I managed to sell the graphics card, but got not a single expression of interest in the TV even after dropping it down to $4, at which point I gave up.

I think games teach a valuable lesson the moment you realize that everything you buy has lost three quarters of its value when you try to turn around and sell it.

They also teach a valuable lesson when you realize you have a limited amount of inventory space and that you're going to have to get rid of most of your junk.

Video games do teach us to sell our junk when we can rather than throw it away, however, and I strongly feel that in general far too much time is spent trying to sell or even give away things we no longer have a use for rather than throwing them away, and often the underlying reason is because throwing them away is wasteful and therefore wrong. My parents taught me this explicitly, and it was a hard lesson to unlearn.

In the real world, you can sell your old stuff. People just don't.

You can sometimes sell your old stuff but for many people it's not worth it for most items - the return vs. the time investment isn't worth it vs. just throwing it out.

Even giving stuff away for free is generally too much effort to be worth it over throwing stuff out though you might think people who had a use for free stuff would have an interest in making it easier to give it to them than to drop it in the garbage.