How did Meiklejohn learn about bitcoin?

Could you elaborate on how Matthew Green, alias Meiklejohn, came to discover and learn about bitcoin? Did he stumble upon it through his research in cryptography and computer security? Or did he hear about it from a colleague or friend within the technology community? Perhaps he encountered articles or discussions online that piqued his interest? Was it a chance encounter or a deliberate pursuit of knowledge in this emerging field? I'm curious to know the specific circumstances that led him to delve deeper into the world of Bitcoin and cryptocurrencies.