I think we must quote whenever we feel that the allusion is interesting or helpful or amusing.
In piano, if you try to force hitting this key and that key, it's very broken. It's not pretty. When you're in archery, you can't try to force it step-by-step-by-step. Then the shot doesn't flow and it's not a good shot. If you just let the performance flow, it's really beautiful.
When the idle poor become the idle rich, you'll never know just who is who, or which is which.

