you might want to stop breathing...
//Are we really breathing in some of Caesar’s last breath?
The story goes that in 44 BC in Rome, Julius Caesar was assassinated by a group of his own senators, crumpling to the floor with a final gasp. This last breath contained around 25 sextillion (that’s 25 followed by 21 zeroes) air molecules, which would have spread around the globe within a couple of years. A breath seems like such a small thing compared to the Earth’s atmosphere, but remarkably, if you do the math, you’ll find that roughly one molecule of Caesar’s air will appear in your next breath.//
https://www.sciencefocus.com/planet-earth/are-we-really-breathing-caesars-last-breath/