I was fortunate enough back in 1997 to be part of a team of Adobe beta testers for an app called K2, which would later become InDesign 1.0. Even having come from Pagemaker, then years of Quark use, and a buggy as hell K2 beta, I could see even then that InDesign was going to thoroughly destroy the competition and take over the industry in short order. It ended up doing just that—despite its lack of features in version 1.0.
James Wamser, an Adobe Certified Instructor, has put together a list of features Adobe has added to InDesign since… well, since ever. I’m not sure how useful his PDF will be to you, but it’s possible that you read through and find out about a feature you weren’t even aware of that’s been there for years.
Download the InDesign New Feature Guide, a 1.5MB PDF, for free.