If there is total annihilation after death, then both the one who strived, and the one who did not, both
have ceased to exist or to enjoy or suffer anything. So the way I see it, we might as well strive, because even if we were to drink in delightful, intense sensual pleasures for our entire lives, party hard and deny ourselves nothing, we would still end up in the same place anyway - absent, non-existent. All of that pleasure, where would it be then?
Gone forever. So we might as well frame our lives as though there is literal rebirth,
because truthfully most of us don't know for sure, but it would be a hell of a mistake to assume there is not, and then be proved wrong as one is actually dying, finally wishing one had restrained oneself more, and meditated more during one's life. "Alas, if only I had framed my life as though there was literal rebirth, I might have partied less, and renounced more."