This might be confusing to think about.
We know that as you approach the speed of light, time slows down, if you were in a spaceship, time goes by quicker on earth.
We also know that distances between planets and such are measured at 'light years'. Meaning that light from a planet if it's 1,000 light years to another planet, would take 1,000 years of our time to reach it.
We also know that photons don't age (which travel at light speed)
Now, if you were able to travel at the speed of light, and you were to go to a planet 1,000 light years away, would you/your body/the spaceship 'age' 1000 years to get there? Or once the spaceship hits light speed, while it takes 1,000 years of our time to reach that planet, would the person and the spaceship itself stop aging and for them that 1,000 light year journey feel like it was instantaneous?? (would definitely create a conundrum if that technology existed then on how to stop or slow down)