Is it hormones?

Friends, the bafflement of Turtle the 9 month old little Corella continues.

Husband and I have found Turtle now lets him stroke him while he's in his cage; in fact he chases after his hand just so he can push his head into it for strokes and petting. However, outside of the cage he will not go near the husband, edges away from him, keeps him out of eye line, and has a little freak out if husband gets too near to him.

As an experiment, I actually placed Turtle on his shoulder, physically. He sat at his back like a little back pack and would not interact with him, and then when he had a chance to get off, he just did and sat behind him out of his eye line - zero interaction.

Is this a prime example of hormones that explains his sudden change in behaviour? Itchyfeet thought it might be. I am inclined to agree only because I have no other explanation; our cockatiels have never had such big behavioural changes. Would be great to get a few more opinions.

IMO there is no way a 9 month old would be hormonal. As far as I know they don't reach sexual maturity until they're 3+ years old.

Little Corella or Cacatua sanguinea

Little Corella or Litlle Cockatoo

Lol I was slightly off the mark there then! But surely thats a good thing....
Could it be moods without hormones?
If it's more than that, as in, if turtle has had a fright because hubby made a loud noise/smell/looked at him the wrong way, we're still back to time and patience?
I think if anyone comes over comfortable enough to handle them, they should incase there's a bit of a one person bond thing developing?

UPDATE - Re: Is it hormones?

Thank you so much for your help, and good to know about the hormones JerseyWendy, and when they become sexually mature. You would think I should know that, owning one.

As an update today, though - SUCCESS! The husband went about his usual morning routine before work and noticed that Turtle was following him around quite a bit (instead of running the other direction). He went to brush his teeth and Turtle followed him into the bathroom, then held out his little foot to show he wanted to climb up his legs! And he did by his own choice and perched on hubby's shoulder! I was still in bed but the husband came in and softly showed me Turtle on his shoulder! I am so excited.

Something definitely got up the little one's nose; what it is I don't think we will ever be sure, but this first step has made me so hopeful and jubilant. I did wonder whether he was bonding specifically with me, but then we both handle Turtle equally. Perhaps he has developed a sudden dislike to males. At any rate I'm not worrying too much now, particularly with this baby step observed this morning. Itchyfeet was right to just give it time, and we'll continue to do so!