There's nothing like receiving a hand-written note in the post. In the age of email, it's an extremely romantic and thoughtful gesture. But one thing you probably don't think a lot about? Why you place that little square stamp in the top right-hand corner - verses, oh, anywhere else.
'When postage stamps were first issued in this county in 1847, there appears to have been a great deal of confusion over how to use them and possibly also where to place them, at least for a time,' Daniel Piazza, Chief Curator of Philately at the Smithsonian National Postal Museum, told mental_floss.
During that time, letters were hand-sorted by postal clerks, so placement wasn't as important. But once machines were introduced in the 1890s, a standard had to be chosen.
Sorry, left-handers: It's believed the location was chosen based on the dominant right hand of most mail handlers. However, today letters are optically scanned so if you want to boycott right hand favoritism, you can.
Sue Brennan, a senior public relations representative with the USPS, says if the stamp isn't in it's designated spot, the letter just ends up in a pile for humans eyes to evaluate.
'Your letter wouldn't be thrown out if you didn't follow the guidelines,' Brennan told mental_floss. 'But using them could speed up the processing and subsequent delivery.' So maybe just don't rebel against the system when you're sending an already-late bill to your satellite provider.