People believe that the certainty, decentralization, and immutability of Bitcoin lie in its distributed ledger based on blockchain technology. This is a completely wrong understanding. The certainty/decentralization/immutability of Bitcoin comes from the distributed account system (i.e. UTXO model). The entire ledger of Bitcoin is uncertain, based on Darwin's principle of the heaviest chain of natural emergence, which is an intuitive system of unpredictable growth.