I read somewhere a kind of touching story about a 15 year old that had been passed around, it had gotten a minimum of attention and was quite aggressive, it turned out that with some concentrated training the bird proved to be exceptionally smart and became the owner's favorite pal, but it still doesn't really care to be handled. The owner got sad thinking about their pal's first 15 years of life.
I recall a professional trainer talking about preferring to start with an aggressive energetic bird that has been labeled un-adoptable, she finds they end up working on tricks with a determination that a laid back super tamed bird can lack.