I'm not saying one should not take human behavior into account, but at least they should get the boundary conditions right, and one of those is that our resources are limited.
That does not mean that additional wealth cannot be created without infusion of additional resources.
I know it's counterintuitive for most people with a "hard science" background... I struggled with it as an undergrad. But economics is not a zero-sum game. I give you $150 and you give me an hour of labor. We've both benefited by the trade. If we are really acting freely, we've both benefited (or we wouldn't have engaged in the trade), so we are both wealthier than we were before. This is the fundamental basis of perpetual economic growth... given a free market* in which to pursue trades, wealth increases as trades are made.
* Free as in some-kind-of-approximation-of-an-ideal-free-market, not free as in no-legal-restrictions-on-activity.
I don't want to be young again, I just don't want to get any older.