Why do we collect things? I've thought about it a lot recently, sparked by looking at all the different cryptocurrencies in my wallet. It's definitely a learned behavior, from an early age. My mind drifts to childhood hoards of rocks, baseball cards, Gameboy games, action figures, and POGs. As I got older, I began to mimic my father's collection -- particularly coins.
One who collects coins is called a numismatist, with the study and collecting of fiat money called numismatics. Yes, I'm quite aware of the irony of writing about fiat money on a cryptocurrency blogging website. Personally, I despise paying for coins/bills for my collection. In fact, I pretty much avoid it altogether.
I like to find items for my collection "in the wild." Just what do I mean by that? I like to look in pocket change, Coinstar return slots, inquiries at the bank, even on the ground in parking lots.
Here are some coins that I have found recently:
1947 "Wheat" Penny - no mint mark
Apparently, these have some value. A quick and dirty search of eBay sold results reveals three sold recently. I'm not sure if indeed these are actually worth $200 but it appears someone paid that much for one. After all, value is determined by what collectors are willing to pay. Another sold for $25. Whether $25, $100, or $200 -- that's much more than face value!
1976 Bicentennial Kennedy Half Dollar 
This one is pretty cool because it is 40% silver alloy. You can tell it has some silver in it from the sound it makes when it hits a rigid surface. I haven't researched the value much on this one yet.
1943 Mercury Dime

So these are 90% silver and 10% copper. This particular one I found is in pretty rough shape, so it wouldn't be worth as much as one in fine condition. I really like the head design on these.
I realized that as an adult the reason I collect things, old fiat currency in particular, is the hope that someday they will be worth more than their current value. Isn't that the same reason for stacking satoshis?