> When I first heard the term, it was used to tell us that us developers need to do our own operations. And we did. Cool.
That is not at all what it ever meant, and is very much the opposite of the original meaning. For what it's worth, I personally think this is probably the best approach now though.
> Then it turned into 'developers need to work with the operations people.' Wait what is this just a mantra or something?
This is sort of it. Calling it a "mantra" is fine, but it was meant to be a cultural shift. It was actually pretty successful, which I think is why most people are a little mystified as to what it was originally about. It has become just the way things are done, so it is difficult to recognize as a change. Back before this change started to happen, developers and operations teams used to be much much more divided. They rarely spoke to each other until applications were preparing for release, and then it was the dreaded "throw it over the wall".
Operators didn't want devs touching their environments and breaking things. Developers didn't want anything to do with production, because once the code was released their job was done. The whole idea was to align these incentives, and to modernize Operations (which was frankly very stuck in old mindsets).
> Now it's just a fancy word for 'sysadmin', apparently?
This is what people mean when they say "if you are hiring 'DevOps engineers' you're doing it wrong".
Anyways, it's basically a dead phrase. If you've been in the industry less than 15 years or so, it's basically meaningless to you. The movement it came from achieved its goals so well that it no longer has any useful meaning. It now just serves as a way to nerdsnipe people who were there into explaining what it actually meant.