Things were still hot but there were at least storm clouds on the horizon at that point.

>Everybody looked at my resume and pointed out that I had never stayed at a single job for longer than a year.

A year means that, to exaggerate just a little, you were basically starting to look for a new job as soon as you started the old one. But, yeah, if someone has moved between jobs like clockwork every year or two, the working assumption of the hiring manager has to be that this time won't be the charm and you'll hop again. Whether they're OK with that doubtless depends on the role.

You might consider just leaving those right out of school jobs from 20 years ago off. If someone really wants to see them, you can tell them but it's not unreasonable to age stuff off your resume if you have lots of jobs.