In classical Newtonian physics, the concept of time is absolute. With his theory of relativity, Einstein proved that time is not absolute, through time dilation. According to time dilation formula, a clock that is moving relative to an observer will be measured to tick slower than a clock that is at rest in the observer's own frame of reference. Through some thought experiments, Einstein proved the time dilation. Twin paradox is also a thought experiment in special relativity. But if we think deeply about these thought experiments, we will understand why these thought experiments must be wrong. Here in this article, I just want to highlight the point why these thought experiments are very much wrong.