Why does the hard, expressive playing still trip me up?

You can play the notes. The technique is there — you proved that long ago. But when the music asks for something raw, something expressive, something that might sound foolish, you pull back. You play it safe instead of playing it true. This is not a skill gap. It is a choosing gap. Each time you sit down, you choose: rehearse what you already control, or stand inside what still unsettles you. Most days, you choose comfort and call it practice. Notice what you actually do when you say you're working on the hard part. You warm up around it. You play near it. You never quite enter it at full weight. The work is the thing itself, repeated, badly, in front of someone, until it is no longer badly.