Where did he learn to do that?

Elliot has been benefitting greatly from all the time he spends with his mom. Mom patiently teaches Elliot as much as she can each day while they have fun playing and laughing.
Recently Elliot was sitting in the Living Room while his mom was drinking some Soy Milk Noel Nog. Elliot knew exactly what it was and he wanted some too. So he dragged mom to the kitchen where he tried to open the utensil drawer. Once the drawer was opened, he reached in and removed one straw. Of course mom had no choice at that point but to share her drink with Elliot too.
He has learned to say "uppie" when he wants up. He has learned to shake his head when he is done eating. He has learned to climb down the stairs. He has learned to draw with crayons. He has learned to feed himself. He has learned to hug people.
He has learned how to say Tate's name.
He has learned to tickle people. He has learned to drink with a straw. He has about a dozen smooth dance moves and will sometimes just start humming some unrecognizable song and start "getting jiggy with it".