I interpret it the opposite from you. Sure you probably won’t make a lucrative living restoring an old car but over time the value will go up. The lesson is more about putting in work that builds value, self actualization and doing something gratifying. I do this with land/property. Sure I could hire a dozer operator to clear it all but the time I’ve spent manually as well as renting a mini excavator for a small price has supplied tremendous gratification and perhaps added $50k in value by opening up a nice view of the mountains that nobody ever thought existed.