I have a slightly odd hobby. I really enjoy stamp collecting. 
Cool, you can also say you're into philately (a word for the study of stamps).
Oh I didn't realize it had an actual name. That's awesome. Do you know when stamps first started being used?
Well the word is derived from a French word and coined in 1864, so that far back at least. Probably a lot longer since mail has been around a while.
Yeah for sure. I'm trying to get a good collection of old and new. Do you know anything about the most expensive stamp ever?
Inverted Jenny
The Inverted Jenny (also known as an Upside Down Jenny, Jenny Invert) is a 24 cent United States postage stamp first issued on May 10, 1918 in which the image of the Curtiss JN-4 airplane in the center of the design is printed upside-down; it is probably the most famous error in American philately. Only one pane of 100 of the invert stamps was ever found, making this error one of the most prized in all philately.
A single Inverted Jenny was sold at a Robert
Philately
Philately (; ) is the study of stamps and postal history and other related items. It also refers to the collection, appreciation and research activities on stamps and other philatelic products. Philately involves more than just stamp collecting, which does not necessarily involve the study of stamps. It is possible to be a philatelist without owning any stamps. For instance, the stamps being studied may be very rare or reside only in museums.
Etymology.
The word "philately" is the English translation of the French "