Carpe diem."

(Odes: I.11)

Leave off asking what tomorrow will bring, and
whatever days fortune will give, count them
as profit.

Time will always exist but you will not. Stop your mind from drifting off into the future if you aren't there yet. Cherish the seconds of your life, live now not tomorrow. -Enlightened-

Well, it does make you realize that life, even at its longest, is still very short.

Why always "not yet"?  Do flowers in spring say "not yet"? 

Seize the day, take hold of it, and make it whatever you want.