Same with Tulsa, she was approximatly 1 years old when I got her from the shelter. They said that she was 2-3 years old. My vet said, No WaY! guessed her age between 1 and 1 &1/2 years. She
acted like a pup. Big time biting issues, did not like men, or children, would lunge at them on a lead.
It took a long time to desentisize her with her issues. Took her out in public with a pocketful of her favorite treats, and when people would ask if they could pet her, I Would put her in a 'sit' and give them her treats to give to her. Her mouth was always very soft, and she didn't grab at the treats. When children wanted to play 'keep away' I would remove my dog. The parents would ask me why I didn't let her play. I would tell them that your childs throat in my dogs mouth is not play, you can feed my dog, but do not ever tease a dog with food. And we would walk on.
Tulsa is now very comfortable with other Men and Children, and I am comfortable when she is around them. My radar is still out there, but I know when she is comfortable and when she's not.
And it changes from day to day.
Don't ever think that your dog is trained for any given situation. Be prepared for the unexpected, and be prepared to react. We have to protect our dogs from stupid people. And there's a lot more of them out there, and too few of us.
John