The guide is a little off in parts, and that was one of the worst offenders. It assumes you're on the first line. Then, you have to hit Escape after typing the colon. Finally, the whole command depends on your having "vnoremap . :norm.<CR>" in your configuration, which I sure don't.

Thanks for that tip! I wandered in here hoping someone had already asked and answered and got my reward.

I mostly use emacs for the past 15 years, but I learned vi about 20 years ago and use it regularly at something approximating level 4, but only for vi (not vim) commands -- having no real knowledge of visual mode or some of the extended commands. One of the hard things about learning vim is figuring out how to search for help -- because "enable dot command in visual mode" (and variants) doesn't turn up anything useful right away. I know I've got the right idea (esp. when seen in a tutorial like this one) but there's some setting or plugin or subtle nuance that I'm missing.