> Anyone who tells you otherwise is either misinformed or lying. 

Duolingo's "Goal" settings:

   > Basic 1XP | Casual 10XP | Regular 20XP | Serious 30XP | Insane 50XP per day

50XP requires no more than 25 minutes of work.

So, according to Duolingo, it is "Insane" to devote 25 minutes per day on learning a language. To learn a language typically requires 50,000 minutes. And that's just to reach a basic level.

I wonder if Duolingo's "Casual" learners realize that that setting implies a 30 year commitment.