On the telly, a painter (forger John Myatt, a man of enormous skill)  is trying to paint a portrait of John Cleese in the style of Matisse. He can't get it right and keeps overpainting the face and doing it again.

This makes me feel so much better!  I've been there soooo many times.  Well, not John Cleese in the style of Matisse.  But the whole 'paint is NOT COOPERATING' struggle is so familiar.