It's absolutely true, you aren't rich if you spend more than you make, unless of course you're getting pedantic about "earn" but I include wealth and holdings in earnings as well. I didn't mean "earn" in the wage sense, just in the amount of money you make/inherit/whatever regardless of how.
That's not spending, that's investing, you still have the wealth; you can resell those antique Ferraris. Money is not wealth, it's a medium of exchange, assets are wealth and converting money into assets isn't spending, it's wise money management.
