Shakespeare said it this way:
Tomorrow, and tomorrow, and tomorrow,
Creeps in this petty pace from day to day
To the last syllable of recorded time,
And all our yesterdays have lighted fools
The way to dusty death. Out, out, brief candle!
Life’s but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more. It is a tale
Told by an idiot, full of sound and fury,
Signifying nothing.
Pink Floyd said it like:
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.
So you run and you run to catch up with the sun but it’s sinking
Racing around to come up behind you again.
The sun is the same in a relative way but you’re older,
Shorter of breath and one day closer to death.
James 4:13–15 states it as such:
13 Come now, you who say, “Today or tomorrow we will go to such and such a city, spend a year there, buy and sell, and make a profit”; 14 whereas you do not know what will happen tomorrow. For what is your life? It is even a vapor that appears for a little time and then vanishes away. 15 Instead you ought to say, “If the Lord wills, we shall live and do this or that.”
If one stives to do things which he/she feels will leave some great legacy or will be known by future generations, then time might be the biggest thief of happiness as one would have a nagging need to spend many waking hours trying to leave that ”mark”. If one achieved that mark through athletics, then time will certainly be short as the body will fade and so will the ability to outrun your opponents to the end zone, outpunch them in them in the squared circle, hit more out of the park, etc., surely a point of depression for some. If it is amassing money and wealth, then time is short for many as they will never obtain more than a substantive living, and they will spend many hours being a wage slave just to have a few trappings and a vacation that is all too short and too long in coming. Once you hit your 40s time ramps up, and it seem those plans you had at 21 and never made it to seems to forever run from you because you have so little time and physical health to chase them.