Jared Yes, for example take two twins. Let's name them Ben and Jerry. Send Ben into space with a very fast space ship (Faster than super fast).
Let's say the ship is on it's way for about a year, while going outragously fast, then returns to earth, again another year. Upon returning, it might be that Jerry who stayed behind is actually multiple years older.
Ben, who had gone to space was seemingly to him on a two year journey. But if the ship went fast enough, the travel actually was way longer in the eyes of Jerry.
This doesn't make any sense, I know, but that's how it works.