From one perspective (perhaps a frustrating one) that's the whole of it.
The dollar bills in my pocket seem slightly silly things, and I think they will seem only more so with time. It's not just their backing, but their scarcity that gives them value. They stop at small denominations because their scarcity is largely an equation of ROI.
The numbers in my bank account seem a bit crazy to me. I need to trust so much that I have so little power over.