All the human beings that ever existed comprise only a very small fraction of the possible templates for human beings.
Indeed, the very fact we exist at all means we have beaten the odds. And not only exist, but exist as conscious beings, aware of our existence and of the universe.
The best way to capitalise on this is to work towards a happy life; what this means, many philosophers already explained - Bertrand Russell comes to mind.
Life expectancy increased gradually for ~200 years.
Who knows, perhaps we'll be among the first to enjoy a life expectancy lengthened by a few decades thanks to medicine - the chances of this happening may not be of the ~'it's practically certain' type, but they're not trivial, either.