It's not that I think people from days gone by were not creative enough to dream up the idea of the Dragon, and say that it breathed fire, and flew. I have trouble with the fact that Dragons are depicted from ancient times in the Far East, throughout Europe, and across the Americas.
How is it that peoples that didn't even know of each other's existence, manage to come up with the same mythological creature with the same attributes.
I could understand it if Chinese dragons were tiny and flew. Whereas European dragons were giant like the dinosaurs and ran around smashing things with their gigantic tales and stepping on things, and the Mayan, Inca or American Indian dragons were water beasts and swam and ate people in the water. The fact that they exist in mythology in just about every culture, and all have the same attributes, such as flying and breathing fire. It's too much of a coincidence!
The logical argument is if they existed where did they go? Where are the bones or remains of these mythical beasts?
In India archeologists uncovered tablets with cuneiform writing that for all intents and purposes were flight and service manuals for some sort of ship that supposedly flew back in their early history. This was either the work of the very first science fiction writer uncovered or the actual manuals of lost ships by an ancient people. Whatever you believe, I find it funny that there was a race between the United States and Russia to get their hands on as many of these tablets as each country could get. To say that people existed here at one time who were as advanced as we are if not more so and then society collapsed and everything was forgotten, is not entirely out of the question.
Dragons may well have existed and went the way of the dinosaurs. Maybe some of the dinosaurs we know of today are just incomplete or we don't have enough remains to get a complete picture of the nature of the beasts and really they were dragons. Maybe dragons existed but left us, traveling to a different dimension or time because of our extreme ignorance.
There is an author by the name Naomi Novik, who writes the Temeraire Series about dragons being used as an air force of sorts during the Napoleonic times. It is like reading a fantasy version of a Patrick O'Brian book. It's the time setting, the warfare in the age of chivalry, where the primary weapons were cannons and swords that make it appeal to me so much.