Poor Ginger - it was self protection probably, terrifying everyone. And even though you were a nice child with hamsters, he maybe just associated childrens voices with fear and dislike. It can feel so personal though can't it? But it was just survival for him in his little mind. And as you say, having this lovely experience now gets rid of that trauma!
Raffy (my bitey one) wasn't that old - maybe about 8 to 10 weeks old when he came to me. I suspect he had been bought for a very young child - unfortunately some people get them for 2 and 3 year olds and don't know much about hamsters. He was given to a rescue after two weeks as "it didn't work out". He was absolutely terrified of hands. But because he was so young maybe I was able to tame him out of it - although he only trusted me. He became terrified again after a vet handled him which was sad.
It's lovely your teens like having a hamster. Our first one was when our boy was 6 - he ended up being mostly mine. By the time our boy was about 12 he wasn't interested in the hamsters any more! Although he did secretly quite like it when Raffy got into his room occasionally!
I think it's good for children and young people to learn that animals have different personalities and that some pets can be quite sensitive
With our first hamster it was the opposite with childrens voices. He seemed to perk up when he heard them! But he only ever knew the one child who was too scared to pick him up! Not for biting (he didn't bite) - he was scared of him running away and not wanting to hold him too tight. And boy he did run away fast sometimes!

He had lots of fun out of cage with childrens toys though and knew our boy's voice and felt comfortable with him. He didn't like men though!
We've had 7 male syrians (and two robos) and all the Syrians have been different. Three shy/lazy ones and two maverick ones and one who was a bit institutionalised (a year old from a rescue). One of our current ones I haven't worked out yet! The shy males seem to have been the most cuddly

But also the most sensitive.
Happy is very lucky to have such a loving home