All that remains constant is the desperate desire to find in the Frenchman's garbled words some key to the secrets of the universe. He called his prophecies perpetual prophecies. Things that were originally said to apply to Napoleon have been reapplied to Hitler and then to Gorbachev, whoever was the bogeyman of the moment. Unfortunately, what people generally do is see what happened, and then find a prophecy to match. He sees in the process evidence of a natural instinct in humanity to search for something metaphysical to believe in.
People are enthusiastic to believe anything.
Having lost religion, they find themselves in a chaos of belief. Where there's chaos, they try to impose order. Nostradamus himself is chaos, but it's easy to convince yourself there's an order there. You're using one form of chaos to make order out of another. His forecast of a revolution which would take place in October and launch a regime which would last 73 years and seven months does seem peculiarly close to the 20th century story of Russia.