However many years anyone may live, let them enjoy them all. But let them remember the days of darkness, for there will be many. Everything to come is meaningless. (NIV)
Yes, if a man should live many years, let him rejoice in them all; yet let him [seriously] remember the days of darkness, for they will be many. All that comes is vanity (emptiness, falsity, vainglory, and futility)! (AMP)
But if a man live many years, and rejoice in them all; yet let him remember the days of darkness; for they shall be many. All that cometh is vanity. (KJV)