Nothing lasts [...] are we just amusing ourselves until death?
It seems to me like you are of the opinion that the finiteness of life robs it of meaning. If so, why not contribute to longevity research? It's only been a couple decades since we learned how telomeres relate to senescence. If enough people work on the problem or donate to it, we very well might be able to crack immortality before you croak. At the very least, that will give you a few more centuries to figure out what the meaning of life is.
You might object that immortality would lead to great wealth inequality, and you'd rather live a finite life than an unfair life. You can only believe this if you believe that the finality of life does not ultimately make life worthless. In which case, why not contribute to the cause of socialism?