would you know what to do when all of your work would essentially be shallow and useless? can you entertain yourself 24h?
Look at the Raspberry Pi - only today a tutorial on creating a basic Pi command-line OS was front page of Hacker News. And yet we all have access to highly sophisticated operating systems with slick GUIs.
Discovery and exploration is its own reward. It doesn't matter if someone or something else has already discovered it.
And even if we're not needed for research it doesn't take the joy out of doing it anyways; Learning is pretty much self-rewarding. Plus there will always be enough projects to keep yourself busy, even if it's "just" organizing the next rave, party or other social event. But before that happens we will have plenty of new frontiers to conquer.
(of course, I would procrastinate all of these things even if I had the time to do them...)