An even easier example would be if people could travel at the speed of light. It is a known, unarguable fact that if someone were to travel at the speed of light for a given amount of time, they could return home and have only aged while a few days, while everyone on Earth would have aged years upon years. I don't know the exact ratio, but you get the point.

One of the only reasons it is not feasible to travel at the speed of light, other than the obvious reasons that a human couldn't withstand the pressure on their bodies, is the fact that any object we transport relies on fuel on some sort. With the weight of fuel needed to even fathom the speed of light, it is clearly not possible to achieve that feat. However, there is experiments being tested and performed at this time that would enable objects to use the pressure of the sun's emitted light to travel at the speed of light via a "parachute" type of aparatus (I can't remember the material for it ATM... Damnit).

Humans measure time through units, as Bob said above, but we clearly can't substitute what we know as time to cover every aspect in the universe.

Oh, and this is being moved to GC.