Yes this could be the potential that humans would need to explore the boundaries of the universe. Even traveling at the speed of light it would take tremendous amounts of time to go anywhere other than our solar system given the nearest Solar system is still 10.5 light years away.
But gravity drives would offer a new kind of speed, maybe one that isn't bounded by speed but actually bends space so that point A and B become much closer. Whatever it is it is still far beyond the human understanding of physics considering physicists are still trying to figure out what actually gives us mass, hence the search for the god particle.
Peace and Humptiness Forever
If you are interested in time dilation, a good sci-fi book to check out is the Forever War by Joe Haldeman.