> there is indeed a chance that the water in your glass is the same water that thirsty dinosaurs were drinking about 65 million years ago.

There's no chance. It's certain.

"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.

And it doesn’t stop there. In the same way, you might currently be inhaling Cleopatra’s perfume, German mustard gas and even particles exhaled by dinosaurs."