There's one big reason many students don't progress as quickly as they can.
It's the pretty-much-automatic avoidance of difficult spots in practice.
And playing the warm, fuzzy, familiar places over and over again.
We've all heard the famous line.
Me: So, how was your progress this week? How far did you get?
Student: Oh, I just polished up the parts I already learned this week.
Me: ...
Student: Jonathan, why are you crying?
This is where spot checks are powerful. But they often require the persistent nagging of a parent or teacher.
Most kids are too new to the planet to understand this entirely on their own. And we adults who have been around much longer take that for granted.
At the beginning of a practice session, don't run the piece. Pick a place you hate. And pound it into the ground for 2-5 minutes. Set a timer if it helps.
When the timer goes off, go on to the next pain in the neck spot. And so on and so forth.
Like a boxer. Jab, jab, right hook, uppercut. Spot check, spot check, spot check, spot check.
As opposed to running around the ring, avoiding the opponent by any means possible.