Bitcoin isn't really all that cool though.

It replaces trust with massive resource consumption and doesn't do a good job of being digital money (it is hard to use safely, it is hard to use anonymously).

Agree, particularly this bit describes the blockchain hype...

> "various 'experts' on it will spring from nowhere to lecture us all about it"

I suppose that partly depends on exactly how novel the blockchain part is, but broadly speaking the world of efforts to combine some of electronic money, cryptography, proof of work and decentralisation was not a new one in the late 2000s. For example Ecash had been hot once https://en.wikipedia.org/wiki/Ecash , while later on Hashcash got a fair bit of attention as a possible solution to the spam crisis. In 2007 (early 2010 is another story) it was definitely more of a deep cut than AI or cloud, though.

definitely Bitcoin/Blockchain. I wouldn't say it will actually disrupt traditional banking empires, but it was the next big thing and 'experts' definitely came out of nowhere and its still pretty cool.