I've got the technique down, and I can play things that used to feel impossible. But when a piece asks me to really pour myself into it, to make it sing, my hands do the notes and something's still missing. I hear it in the recording and I know I held back.
More people experience this than they realize.
You have the technique but can't yet play with real feeling.
If this sounds familiar, the Library can help you find the bigger picture.