A teacher, who gives you some tasks which are above your real skill, may overvalue you...
and why would that happen?
May be, in that case, he is not a skilled teacher or a beginner one and need time in his teaching.
and I wonder if some people are more hard to teach than others. I mean, people sometimes need psychological help, eg some don't understand how to practice simple arpeggi. It is easy to be confused. I guess a student overthinking the details like how to move one's thumb for some arpeggi is something most teacheers have a difficult time dealing with. Getting stuck or missing the details can be a big issue. I have a amazing piano teacher now and he knows how to deal with this.
It's so easy to get stuck or sometimes miss the details, right? Have you ever experienced this?
It's like you can play something kind of ok, ie you have good technique for it, but overthinking messes things up for you, right?
And I guess a lot of issues for me and others are with aural skills and I'm not just talking about playing by ear. Even technique exercices requires good aural skills but in a nother way I guess.
I often find that aural skills are the hardest to teach. You can know all the theory in the world but have extreme issues with aural skills. Just because you know lots of theory doesn't mean you can play a simple tune by ear. Your theoretical knowledge will fool you.