that bitcoin actually works, and has continued working, from genesis with one user to today with millions of users.

how much Satoshi got right when he launched bitcoin. in retrospect and compared to everything that came after, that is quite amazing.

how difficult it is to use bitcoin privately. simply generating a new address and using Tor (as Satoshi suggested) is far from sufficient. I'm convinced that adoption of some kind of zero-knowledge protocol like Zerocash is needed to give users both "dummy-proof" and "future-proof" privacy.