But he IS having a good life!
He has Bobby, his bestest friend to follow around and snuggle with, and you and your DP to give him everything he desires. Honestly, he wants for nowt.
Is he happy? I get the feeling he is, and that's the main thing.
I know I go on about my lot too much, but he reminds me of one of my old guineas, who, when he was a few months old had a severe ear infection. I was away at the time, and when I saw him I thought I was taking him to the vets to be pts. He was so, so weak, and despite the antibiotics for a few weeks couldn't manage to get out of one carry box as the lip was too high at 1 cm.
He survived (outlived his brothers) and although he was never 'right' he was the happiest wee lad you could meet. He was hyperactive, ran in circles and in a world of his own. He loved nothing better than escaping wherever he was so he could cause chaos elsewhere!
What I'm tying to say is that he was ill, and if you compared his life to that of his brothers you'd have pitied him, but actually he was happy as he was. Please stop comparing Teddy and Bobby but judge Teddy by himself (if that makes sense).
And if he's happy, which it sounds like he is, than you should be too!