I think it is a never ending journey because if you are materialistic and like to collect things, once you finish collecting one thing you will crave another. You get everything in one set and say "well I have all these, time to play them all." Then you get money again and something inside you makes you wonder what to do with it. Since you are used to collecting, your brain tells you to satisfy that urge of doing what you are used to.

Or sometimes if you get a nice collection the next thing you want to do is rather than collect more, buy things that will make your current collection look better or be easier to access, such as new shelves or cabinets. Some people run out of room but want to keep their stuff so they get a storage unit and put shelves in there.