The phrase clearly reflects that he understood the importance of what he was doing and wasn't going to waste time on naysayers. Progress is often like that: one guy moving forward and seeing things clearly, with a few people behind him shouting, “He's crazy!” “That's impossible!”
I ink the part that Satoshi wrote it.
They were discussing about scalability and transaction rate there...
As I understand it, they were discussing the issue of the average confirmation time of 10 minutes, while Satoshi already saw a possible alternative, although in general that phrase has been taken to refer to the Bitcoin project as a whole. Regardless, it is a symbolic phrase that goes beyond its original context.
By the way, we have an example of good use of AI in the forum in the OP with the image. Kudos for that.