Not a bad thing, but once I learned some of those basics, I no longer had fun toying around with animations and creating, and instead spent my time writing classes and functions. It became a lot harder to 'hack' things together, and, for me, less fun.
And besides that, plenty of real coding tools already existed, and HTML/CSS/JS was improving really quickly as well. So I ended up learning those instead.
All of that was actually great for my design career, but Flash just didn't have a place anymore. And I'm still sad about that.