The problem is that the boy never does what he is told.
I’m struggling with the part “lo que se le dice”.
Would someone please explain this to a beginner? Thanks in advance. 
Update: I believe it’s the passive and that “lo que se le dice” translates to “that which is said to him” (or, literally, “that which says itself to him”).
It’s “se dice” = “man sagt” again.
el niño nunca hace lo que se le dice
der Junge nie macht das was man ihm sagt
You also often hear “Cómo se dice?” - “Wie sagt man?”
Ahh, I think I recognize my error.
It’s the same story we discussed in that other topic.
“se” is overloaded with so many different meanings, I find it hard to keep them apart.
Thanks again for the clarification! 