Some more learning from last week’s music performance. When you think you have something memorised, you actually still have a long way to go.
Here is the process I went through with a pretty simple song, still it took time:
Hit the right chords when reading the chord letters on a piece of paper
Hit the right chords when starting the song from scratch, without paper
Consistently getting the chords inversions and finger positioning right (rather than making them up each time you remember to place a chord)
Being able to do the above with random interruptions, without starting from the start: a mistake (by you or a band member), a quick start-stop to rehearse a certain piece
Not thinking at all about chords anymore, just hitting the right thing based on the lyrics, music you hear around you.
When you wing a story on the fly, prompted by a slide that you see on the projector, you are at stage 1 when it comes to presentation preparation, and have 4 more steps to go.