The bright glare of youth blinds you to the rushing road beneath your feet. You think only of all your life ahead of you, far more road before you then behind, and you eagerly race toward it.
Then life actually happens, insidiously, but you are barely aware of the increased speed of travel. You get accustomed to moving at nearly the speed of light. Everyone else is, so you don't even know you are.
Then, at some point, you slow down, hopefully by choice but sometimes not. And you realize there is far more road behind you then before you.