Don't presume that you are immune to optical illusions or hoaxes.
When you travel, especially when you are sightseeing, you try as hard as you can to take in everything around you. However, your brain can interpret data as what it expects to see, rather than what the eyes actually see, so try not to jump to conclusions. In an earlier Camelopard tip, I warned of the danger of always believing what you think you see. That wasn't the only example of being fooled myself. Here are two more examples of how my brain misinterpreted what I saw. Both relate to UFO phenomena.
In 1965, I was on a flight from Aden, in what is now Yemen, to London. I was aboard a Comet 4 if I remember correctly. At one stage, on the left of the aeroplane, a silvery metallic cylinder kept pace with the aircraft. It was too fast to be an airship. The flying craft from Buster Crabbe's Flash Gordon series made me consider that the object I was seeing was an alien craft, an Unidentified Flying Object. However, another passenger, more experienced in aerial phenomena than most of the passengers, explained that it was a sort of mirage created by atmospheric conditions. It was actually a reflection of the aircraft, although atmospheric conditions distorted its shape and colour. Early UFOs were sometimes reported by World War Two pilots. I am sure that some reports resulted either from high altitude atmospheric phenomena not being well understood at the time or because there was not much time available for teaching war pilots aviation science, except that which was absolutely required for combat.
Many years later, near Johannesburg in South Africa, I watched a glowing sphere moving slowly through the night sky. I was convinced that I was looking at my first genuine extraterrestrial spacecraft! After some time, however, I heard the unmistakable sound of a helicopter. The illusion was most probably created by the pilot flying with the cabin light on and the tail light off. I have little doubt that it was a deliberate hoax. Not very much later, I read a newspaper story about many people in the area having seen a UFO. My parents also believed that they had seen the same UFO and said that it had brought the traffic to a standstill! It seemed so real that they were unsure of my explanation that it was a helicopter.