I'd say around 2 years. I stopped using Flash altogether for a long time and had to re-learn most of the stuff.
Started with AS2, made "tests", banners and small apps for myself all the time. A couple months ago I decided to move on to AS3 and I've stuck with it ever since. I've recently started to focus more on Flash and I've done a few jobs already and made some good money.
I'm not too satisfied with my progress, I've lost valuable time. Plus it's always good to push yourself. But yeah, I'm doing much more complex stuff than before. I'm trying to completely understand OOP, still having some trouble with the organization aspect mostly.