The phrase "to live fully" comes to mind, but is not quite what I'm looking for. I'm writing user stories in the form of
As a ______ [word], I want this and that, because I will lose less time.
so the intended usage is describing a customer or a user who wants to get the most out of his time and life, who wants to live his life to the fullest.
Alternatively, if this is too narrow, is there a word for someone who in general wants to get the most out of things he has or things he endeavors?