A lot of people saw Bitcoin coming. Few people envisioned it exactly the way it works now.
Nobody knew the full solution on how to create it so it would actually work, but there was a large crowd of mathematicians, cryptography enthusiasts and early digital currency developers who were looking into this. Hashcash was invented by Adam Back in 1997 mind you. Some people today were already trying to invent proof-of-work based currencies 10 years earliers and the public somehow lost interest. Plenty of fiction back then was already talking about the idea of digital credits. The words 'bit-coin' and 'bit-gold' 'e-gold'  'e-cash' were pretty popular.