My wife and I were collecting old notes since 90's, one day we tried to catalogue notes and old coins. These notes are coming from our close friends and relatives. But most of it are from the money changed during our travel for vacations and also in my line of my work.
Early this year I was in Ecuador. I changed 100 dollars in the bank for sacagawea 1 dollar taking good luck on finding cheerios dollar but no success. The zeros now are gone, they are using US dollar. Their notes tells their history mere looking at them.