My Umbrella Cockatoo exhibits no screaming, neurotic behavior. Am I lucky? Is the worst yet to come?

'Louie' is 5 years old. A college girl had him; she moved back home; she and her Mom cared for him. The Mom was allergic to him. I bought him, and after the first couple days, he was comfortable with me. Sometimes I rough-house with him a bit and that's the only time he really vocalizes. I'm thinking i must be incredibly lucky, considering what I've read online about Cockatoos!

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