Describe that someone’s explanation matches your knowledge level

In German, in the context of knowledge transfer from one person to another (or to a group) you can say

Du hast mich gut abgeholt. (literally translated You picked me up well)

This sentence means that the "teacher" taught the subject at exactly the right level of knowledge, so the "student" was neither overwhelmed by the topic, nor did they already know everything they were taught.

So basically, if the student had 50% knowledge of a subject and the teacher started teaching at 25%, it would not fit the sentence. Neither would it fit if that teacher started teaching at 75%. I hope you understand what I mean.

How would you express this in English so that everyone understands? I know of the phrase picked up where I left off, but that doesn't fit well for the topic of one person teaching another.

You could use the word meet (in the sense of connection or joining), as in "You met me at my level."

I'd suggest variations on Pitch, such as the phrases Pitched it well or pitched it just right/at the right level

5. (tr) to aim or fix (something) at a particular level, position, style, etc: if you advertise privately you may pitch the price too low.

In your example sentence it might be translated as 'you pitched the class just right for me'.

As per Kevin's comment, this would seem to be primarily a British-English usage.

I would say it was "right at my level."

You have "high level" explanations; "overviews" - like a picture of a building. You have "detailed" level, where you have the pipes and walls, such as a blueprint provides.

But when you look for an apartment, you want a floor plan of one residence. That would be "an appropriate level" of detail.