Untranslatable, I think it is not at all suitable to be a duo example.
Unfortunately this Adverbs 2 lesson is rife with many idiomatic phrases that the dictionary does not pick up on! Ridiculous that they do not even include phrases like "ab und zu"!
I don´t get this, sometimes I just feel like quitting this....
Don't give up! Learning a language always feels like this. If your brain feels like it is drowning and gasping for air, it just means that it is learning. :-)
Yes, that's why yawning in classrooms can seem uncontrollable. It actually means you're paying attention.