@Samurai Equine
Now that Boulder was a bit more clear headed, he spoke with the doctor without making a break for it again. there was still a guard pony outside the door in case he tried something however, considering the fact he had sent a few grown stallions flying earlier in the morning during his escape attempt. They weren't questioning him on his preternatural strength so it didn't seem THAT uncommon, though it was rare enough that no one else he ran into in the hospital had it.
He chose his words carefully as he spoke to the doctor. From the way they were treating him, Boulder's body seemed to be younger than the one he had in his own reality. While back home he was a high school student this was clearly something more akin to a grade schooler, perhaps younger. He couldn't really tell since a lot of these ponies looked the same to him with only different colored coats and manes distinguishing them. The Stallions seemed to be stockier with broader jawlines and sounded more masculine, so he could differentiate little things like that, but remembering faces was going to be a challenge.
Boulder tentatively explained that he did not remember what happened before. The only thing he remembers was his time with the Diamond dogs and escaping from them, as well as his own name. This wasn't a lie in the technical sense, given that this did account for the entirety of his memories of being in this Equestria. He explained what the Diamond dogs were, what slave labor he performed for them, and how he escaped from their clutches. From the shocked and empathetic looks he was getting towards his amnesia as well as his treatment under those canines claws, the story seemed to be carrying water at least.
He'd need to be wary of potential mind readers though. It's rather clear to Boulder at this point that these ponies had some kind of powers, like the ability to levitate him off the ground or his own ability to burrow through the earth extremely fast. Somepony with the ability to glean into his mind somehow would be able to find out that he wasn't actually a pony, at least on the inside, and that could cause problems. They seemed nice enough, but he was waiting for that other shoe to drop.