[sanderjd]

How many of these things are "careers", though? To me, many of these examples sound like doing a bunch of different jobs, not careers.

Was being a factory worker a career, or was that a job you were doing before you started your first career as a researcher?

But I do think this thread is making me realize that this is probably a boring dispute over what "career" means.

[jvanderbot]

Yep - that is the issue. You can define it however you want so it's fairly arbitrary. To answer your question - given it was a major life direction change, I consider it a career change. I'd say a career change probably involves a similar life change in all cases.