A lot of us felt like such pioneers in those days. Writing frontend web apps was an emerging and rapidly changing art. Those of us on the bleeding edge read Ajaxian.com and Douglas Crockford. I was writing internal SPA apps for Firefox+IE6 with Prototype.js and ExtJS.

My co-workers strongly disagreed with my approach -- to build for Firefox first, then hack it to work on IE. "Why bother when 95% of your users are on IE? That's a waste of time."

But those apps are still being used, almost 2 decades later, with no modifications required (besides a couple of weird edge case hacks for later versions of IE).

Always bet on the web.