I'm very fuzzy on how time slows down (or speeds up) as certain milestones (speed of light) is approached.
From the little I know, time can either speed up or slow down depending on the velocity with which one is moving. The closer that velocity is to the speed of light the slower you age to observers at rest. But privately, you age the same amount.
If person X was moving close to the speed of light for 50 earth years. They may have only aged a few days, whereas person Y on earth aged 50 years.
Is this accurate?