The Big Bang Theory returned from winter break and its big baby arrival with a low-key episode where the gang recapped what they did over the holidays. Not much happened, but it was still a different sort of episode structurally than what The Big Bang Theory usually does. It's told mostly in flashback, with a post-holiday gathering at Leonard (Johnny Galecki) and Penny's (Kaley Cuoco) serving as the frame device.

Sheldon (Jim Parsons) and Amy (Mayim Bialik) had the most interesting break, since Sheldon was confronted with the fact that the rest of the world — including his own mother — thinks he's weird, which he refuses to accept. If this were a cable dramedy, Sheldon would be a tragic antihero who can't see his flaws even as they're destroying him. Anyway. He and Amy went to visit his super-religious mother Mary (Laurie Metcalf) in "The Lone Star State — that should be its Yelp rating."

Sheldon didn't want to tell Mary that he and Amy are living together, because he's certain she'll give them a lecture about how sinful that is. But Amy forces him into it, and he's surprised by her nonchalant response, and asks why she isn't mad.

"I would prefer you weren't living out of wedlock, but given your special circumstances, I'm very happy for you," she says. Hmm, and what special circumstances would those be?

"By your third birthday, you had memorized over a thousand different kinds of trains, and I never imagined a woman getting aboard any of them," says Mary, in the line of the night.

Jim Parsons, Mayim Bialik and Laurie Metcalf, <em>The Big Bang Theory</em>Jim Parsons, Mayim Bialik and Laurie Metcalf, The Big Bang Theory

Sheldon can't believe that his own mother thought he would be alone for his whole life because of his difficult personality, which he can't accept. He overreacts by walking around the house with swim fins on his feet and a pair of tighty-whities on his face, "just being the unsocialized eccentric my mother always thought I was."

Amy and Sheldon finally leave the house to decompress, and Sheldon goes through a belated rebellious phase by getting his ear pierced.

But then Mary makes him take it out.

And then Amy puts alcohol on the wound.

And then we're back at Leonard and Penny's, where they say that they had the biggest fight they've ever had over the break. It was ostensibly over Penny watching episodes of Luke Cage without Leonard, but really it was about the Christmas tree fiasco — Leonard and Penny chopped down their own Christmas tree and it didn't go well. That's it. This was by far the weakest plot of the episode, so let's move on to Howard (Simon Helberg) and Bernadette (Melissa Rauch).

The new parents spent the holidays taking care of baby Haley, of course. But they're struggling, because Haley won't stop crying — and since Halley is voiced by Pamela Adlon, those cries are HUGE. Howard and especially Bernadette are exhausted and frustrated. When Stuart (Kevin Sussman) shows up and gets Haley to stop crying almost immediately, Bernadette loses it, because she thinks the baby hates her and she's a bad mother. Later, instead of sleeping, everyone is crying, even Howard. But then Bernadette gets the baby to fall asleep by climbing into the crib and sleeping cuddled up with her. It's very sweet.

I would have thought The Big Bang Theory would spend more time with the new baby in the first episode after her birth, but this is still Sheldon's show. I worry that the baby will only come up when it's convenient for the story and not actually be a part of Howard and Penny's life in a real way, a problem which has plagued many sitcoms over the years. But we'll see how the rest of the season goes.

The Big Bang Theory airs Thursdays at 8/7c on CBS.

(Full disclosure: is owned by CBS.)