Time...

...
Tired of lying in the sunshine staying home to watch the rain
You are young and life is long and there is time to kill today
And then one day you find ten years have got behind you
No one told you when to run, you missed the starting gun

And you run and you run to catch up with the sun, but it's sinking
And racing around to come up behind you again
The sun is the same in the relative way, but you're older
Shorter of breath and one day closer to death

Every year is getting shorter, never seem to find the time
Plans that either come to naught or half a page of scribbled lines...

(Time by Pink Floyd)