Why is the universe so much bigger than us?

Imagine humanity is the only intelligent and selfaware lifeform in the universe. Isn't it the disparity of scale that boggles the mind, with this supposition? Such an unimaginably vast universe, temporally and spatially; such a tiny portion of that universe given over to us. But here's an SFnal hypothesis: imagine if the universe processes information by embodying it; and that every individual human branches into alternate versions (possibly two; perhaps four) of her/himself at every moment. The 'supplemental' universe could just be as big as it needs to be to handle such vast quantities of data.