Pergunta, de onde vem esses 2 anos citado?
Não lembro de ter lido já qualquer informação sobre o tempo que Satoshi ficou desenvolvendo a ideia.
Unica coisa que lembro é talvez sobre a questão do dominio, a data de registro (?) Não lembro a data exata, mas tinha na mente que era algo de meses e não anos.
Alguém sabe desses 2 anos?
Usando o Ninjastic Space, encontrei essas citações aqui do fórum:
How long have you been working on this design Satoshi? It seems very well thought out, not the kind of thing you just sit down and code up without doing a lot of brainstorming and discussion on it first. Everyone has the obvious questions looking for holes in it but it is holding up well

Since
2007. At some point I became convinced there was a way to do this without any trust required at all and couldn't resist to keep thinking about it. Much more of the work was designing than coding.
Fortunately, so far all the issues raised have been things I previously considered and planned for.
e
14. Is there a way to see how many bitcoins have been generated this far? And how old is Bitcoin already?
14:
For now, you can just multiply the total blocks by 50. The Bitcoin network has been running for almost a year now. The design and coding started in
2007.