"[W]e regret the fact that a particular session of lovemaking has ended, not because its end spells its meaninglessness, but simply because a good thing has ended. It is therefore possible to lament the end of an affair without at the same time condemning it as meaningless: they are seemingly incapable of performing this intellectual act, who cannot envisage the end of a life without at the same time judging the whole of it to be meaningless."
Thus wrote I on p. 28 of The Meaning of Life. It's a simple point, really, but let me put it differently: The end to a life wouldn't be regretful, if we didn't regard the life as meaningful.
Still confused? Let's spell this out. There's two possibilities, A and B:
A. Life is meaningless.
B. Life is meaningful.
If A is true, then death is not a bad thing.
If B is true, then death is bad because it puts an end to something good. It doesn't make life meaningless, though, because if it did, then A would be true, and we already examined what happens in that case: There would be nothing for us to lament: whatever I'm doing at this moment - say, eating my favorite brand of ice cream - is already meaningless, because I'll die one day. Enjoying ice cream doesn't become meaningless when I die: it already is. Enjoying ice cream is as pointless now as it will be after my death. There's no reason to fear death or condemn it, because it won't alter anything. Unless of course B: in that case yeah, death sucks!
So next time you find yourself in the doldrums, instead of saying, "The fact that I'll die proves everything is pointless", say rather, "I hate death, because life is good, and death puts a stop to it". You'll be equally miserable, but at least you'll die a logical man!
Two train-similes to put this article to bed:
"Death is not the natural destination of life, but rather is like a robber who arrests the train midway in order to steal its riches." - MOL p. 28
"The tracks we lay for our future outrun us; Death waits at every intersection like a conductor ready to digress us toward an awful, but common, fate." - MOL p. 116