Well, as a gamer at heart, I of course found a way to hack the achievements presented in duolingo. (An awesome free language app, btw.)
I noticed my fluency rating had slipped from 22% down to 12% in the app over a few weeks. My bad for not being consistent.
When it slipped after I completed two daily lessons, I knew it was time for action. And since I quit WoW Monday, what other achievements am I getting? None, I tells ya.
Then I noticed a link to my dashboard. Voila! The web version has tons of other options like progress tests and timed tests. Neat!
After a timed tests I was back up another 5 percentage points: 17%. Oh, now it was ON.
After a few more tests, all easily within 30 minutes or so, I was back to my original 22%. Then I beat that.