How to learn: by notes or key positions?

Title says it all.

This is something that always bothered me... I remember my dad telling me waaay back that pianists learn to play a song on the piano by learning its notes, but right now I'm just learning the keys I need to press on a piano. I can mentally convert from keys to notes, but not instantly...

So, is learning a song by key positions a Good Thing, an Acceptable Thing, or a Bad Thing?

I dont really know what you mean, but we usually start out by learning the names of the keys on the piano, then the scales. At the same time we learn how to read a sheet.

If a sheet is written in F major we know that that's the scale we're going to play in. Then we read the sheet and play them on the piano.

Isnt a key and a note basically the same? If you rpess the C key on the piano you play the note C.

I think I get what the OP is referring to. That's exactly where I am at the moment.

I really have been learning pieces only by key position. I don't understand the concept of, "ok, this piece starts in C, then moves to G (V ?) then to something else and then back to C"

At the moment for me it's, "ok, this white one, and then this black one and those 3 together with the left hand."

I don't think it's necessarily wrong, but I think it helps with both memorization and playing to understand what's actually happening in the music, and I can't do that yet. I think it becomes even more necessary in the longer pieces.

In fact, I posted almost this same question to Andrew yesterday:

https://afpa.hooxs.com/ask-andrew-f9/help-understanding-bach-bwv-999-t1409.htm