This common explanation and "proof of relative time" contains a massive logical error. Just because you have a clock that runs slower because you're moving fast does *not* mean time is traveling slower for you. It means your clock is running slower because you're moving.
Most people will believe anything because most people don't actually think anything all the way through.
Professor Brian Cox explains using a simple light clock, time is not absolute. Because the speed of light remains constant, a light beam in a moving clock traces a longer, diagonal path from an outside observer's perspective, proving that moving clocks run slower and time literally bends to the speed of the observer.
This reveals a mind-bending reality: if you journeyed through space at 99.94% the speed of light for ten years, you would return to an Earth that had aged 29 years; making you a literal time traveler into the future.