Calm Puppy

I never knew there was such a thing but (sh) our puppy is quite a calm little guy. I'm not sure if it's just a phase or what. I was expecting, well, mayhem! He politely eats his food, goes outside to run with kids,  and practically wipes off his feet on the mat before he comes inside. He's just... sweet. Mellow. Perfect. We were wondering about his hearing, but the vet says he seems to be hearing fine. He does roll two lazy eyes towards the source of a sound, but doesn't startle or cock his head or anything. He's just... mellow. This is just so unlike the puppy experience I was braced for (and still am braced for, really!). Could he change? Could he get a little more wild? Or is this it? So curious to see... He's in good health, other than testing positive for giardia, but then we are the poster children for giardia (no longer, thankfully) so we can help a puppy through that too. Seems like the medication is simpler for the puppy than it was for the humans. He did bark when Mrs. B. (formerly of next door) dropped in to say hello (but wasn't allowed in because of a stomach virus that had DH in the emergency room for several hours!), so we're glad he'll be a bit of a watchdog. He's just a dear, and I don't think of myself particularly as a dog person either. But this one? He's special.