Would an eternity of nirvana necessarily counterbalance eternity itself?

imagine the best thing you have ever experienced. better, imagine, if you can, every good thing you know rolled into your consciousness. and now imagine that is all there is and all there will ever be for eternity. no end to this heaven/hell of eternal stability and perfection, and no way to die as everything mortal decays and everything immortal becomes familiar. any and all accomplishments of any kind at all become meaningless by the very nature of the infinite. now answer me why we strive for eternal life