Which makes our current system of isolating children by age group and then leaving them virtually un-attended look somewhat insane.
He went from being a bit lazy and not really trying to walk (he did stand up by holding on to things, and shuffled sideways) nor really say actual words, to trying to say a couple new words, standing up in place and trotting around the house all the time.
I did 2 years in elementary teaching back in uni, one thing that stuck to my mind is that imitation is one of the main learning strategies in childhood, up to high school age where discovering their own individuality takes over a bit.
As for the daycare factor, you could sure think of an equivalent 'beam' in your home. That could've been a chair, a something 'interesting' higher up, say, mommy's voice coming from above - anything!
Babies find the ways. Unless the home environment is devoid of attractions and baby is confined to safety of an infinite carpeted floor surrounded by soundproof glass. That's a sci-fi kind.
How do you figure? Maybe it depends on the person but every interaction I have and have had with people has been framed by the lens of my relationships with family, not my peers.