Old parrots do learn new tricks! When it comes to diet, I have found that, although it means a huge waste of money, in the long run it pays to keep on insisting with items they seem to dislike because, sooner or later, they will eat them. I have found they are very much like people in the sense that, we, humans, as we get older, change our prefernces and stuff we couldn't stand when we were children or younger, we start to like and even love.
Very nice to see you back!