According to the theory of relativity, as a person approaches the speed of light, time appears to slow down for them as observed by an outside observer. This phenomenon is known as time dilation. However, from the perspective of the person traveling near the speed of light, their perception of time remains unchanged.
This might seem counterintuitive, but it's a consequence of the way time dilation works in relativity. When an object is in motion relative to another observer, their perceptions of time and space can differ. The person traveling near the speed of light experiences time passing at a normal rate from their own perspective. It is the external observer who observes time slowing down for the moving object.
From the traveler's point of view, their own biological processes, thoughts, and physical experiences continue to unfold at their usual pace. They do not subjectively feel any change in the passage of time. This is because all the physical processes within their own reference frame, including the functioning of their biological systems, are affected in the same way by time dilation. Therefore, there is no subjective perception of time slowing down for the traveler.
It's worth noting that time dilation is a complex and fascinating aspect of relativity, and it has been verified experimentally through various experiments involving high-speed particles and atomic clocks. While it may seem peculiar, it is a fundamental consequence of the theory and has been consistently supported by experimental evidence.