There are people who manufacture ‘collector’s items.’ They will make, say, 300 coffee mugs celebrating a rock star and promise that no more will be made. Even if they keep their promise–and their record isn’t good in that respect–few such items ever become valuable. Why? Because of their supposed value, all of the mugs are still around after 30 years and are not worth much more than when they were sold.

On the other hand, the same rock star has a concert which is attended by 80,000 fans, all of whom buy a ticket. Thirty years later, one of those 80,000 tickets is worth a great deal. Why? 79,934 people threw their tickets away. When one of the remaining 66 is sold, one of the 79,934 says: “Hey, I was there, and I want that!”