I hope this story isn't too silly, but I thought this would be a funny scenario.
Bofur said a silent prayer of thanks to Mahal. His cousin was going to live! It had been a long three weeks since his head injury, but today Óin had reassured Bofur that Bifur was now on the mend.
Another month passed. Bifur came to live with Bofur. He sure needs looking after, Bofur mused. Bifur had recovered surprisingly well, but some things about him had changed. He didn't speak much, mainly using Khuzdul and sign language to communicate. Among other things, he had developed an obsession for green, leafy vegetables. But that was nothing compared to what Bofur witnessed one afternoon.
He had finished bathing, and looked around for his hat. It wasn't hanging on the peg where he had left it. Strange, he thought. He poked his head in Bifur's room. "Hey Bifur, have ya seen my-" he broke off and his mouth dropped open in shock.
Bifur was sitting on a low stool, clutching a cup of tea and wearing Bofur's hat! He seemed to be staring blankly at nothing.
Bofur was thoroughly confused. "Bif, since when do ya drink tea?" he asked, moving towards his cousin.
Suddenly, Bifur snapped to life with a wail of, "Gone! It's all gone. Oh, it's gone, bye-bye, woo, see ya!"
Bofur was stunned. "You're speaking in the Common Tongue? What's gone? And what are you doing with my hat?!"
But Bifur went on as if he hadn't heard. "One minute you're defending the whole galaxy, then suddenly, you find yourself suckin' down Darjeeling with," he dropped his voice to a whisper, "Marie Antoinette and her little sister." He chuckled and waved at the two imaginary dwarf women.
Bofur rolled his eyes. "I think you've had enough tea for today. Let's get you out of here, Bif."
Bifur suddenly jumped up and grabbed Bofur by the shoulders. "Don't you get it? You see the hat? I'm Mrs. Nesbitt!" Then he started laughing in such a crazed manner that Bofur visibly winced.
"Snap out of it, Bifur!" He snatched his hat back, but resisted the urge to smack Bifur across the face with it.
And Bifur did snap out of it. He never spoke in the Common Tongue again after that-until one day, his axe was finally removed. His first words were, "You know where you can stick that?"