My favorite was block chain. A company I used to work for that was not a tech company, suddenly going on about the block chain. I saw former, non technical colleagues that were still there write long authoritative LinkedIn posts about the advantages of the block chain and it was incredibly cringey because I am not sure what they thought the block chain was, but I am confident they didn’t understand it at all.

Before the iPhone was the iPod, and before the iPod I had an iRiver mp3 player. There was certainly a trend and only Apple's product survived that one.