During a multiplayer game in Leonard’s apartment, the guys are losing and call for Sheldon to help them. Sheldon tries to fire his weapon, but keeps jumping instead as all of their characters are killed. Sheldon is worried that he used to be very good, but that he is no longer the wunderkind he once was.
At a girls’ night out, Penny is surprised that Bernadette can drink while breastfeeding. Bernadette counters that the yeast helps with milk production. Amy calls that a myth which irritates Bernadette. Penny runs into her ex-boyfriend Zack who is now engaged. Zack invites Penny and Leonard to dinner with his fiancée.At the comic book store, Sheldon is discussing his recent humiliation in the video game. He has read of some research called “super aging” which suggests that by performing difficult mental tasks, one can actually improve the structure of your brain. Leonard suggests crossword puzzles; however, Sheldon retorts that wonders how it’s difficult to do crossword puzzles, Sheldon says it’s about pushing your brain out of its comfort zone and to the point of exhaustion.
Leonard is not excited about spending an evening with Penny’s ex-Zack. After they meet, Zack apologizes that his fiancée couldn’t make it.
Back at the bar, Zack discusses Leonard’s government project and Penny’s sales job. She is not happy about it so Zack mentions that he’s got an opening in his company as head of sales.
Driving home, Leonard asks Penny if she’s serious about taking the job. She thinks the offer is great since she has sales and restaurant experience. And then she asks Leonard if he is jealous and wants her to stay in a job that she is not happy with. Leonard replies that working with an ex-boyfriend just isn’t very smart.
Amy arrives home and finds Sheldon trying to learn to ride a unicycle. She heads for the bedroom; however, Sheldon needs help getting down.
Leonard gets advice from Howard and Raj, while Penny is talking to the girls. Penny insists there’s no reason for Leonard to feel threatened since Zack is engaged. Bernadette tells Penny she wouldn’t let Howard work for an ex-girlfriend. Raj thinks that Penny will push back if Leonard tries to stop her.
Sheldon boxes up the unicycle telling Amy that he is quitting. Amy says that he may be quitting just because it is hard thus making Sheldon mad and he leaves.
Elsewhere, when Penny returns to apartment 4A, she asks if Leonard wants to talk. Penny says she understands this job would make Leonard feel uncomfortable. Leonard tells her he doesn't want her stuck at a job she doesn't like, so he says if she wants to take the job, he’ll find a way to deal with it. Penny says no to the idea as it would make them both miserable, so she’ll stay where she’s at. When Leonard says now he feels like he’s being selfish and holding her back, Penny doesn’t disagree
In their bedroom, Amy brings Sheldon a cup of tea. He is quickly reaching the peak age for those who win a Nobel Prize. Amy then suggests he spend less time on comics and video games. No. She then asks if it would be so bad if he never made a breakthrough discovery and instead spent his life doing solid, dependable research, surrounded by friends and loved ones who appreciate him. Sheldon thinks that Amy’s cute and announces that he is going to go learn how to walk on stilts.
At home Penny asks Leonard if he was sure that she should take the job. Yes. Penny calls Zack and learns that there is no offer because his fiancée didn’t like the idea either. After finishing the phone call with Zack, Penny tell Leonard he was right.
When Bernadette goes into her kitchen, she finds Howard and asks him where he was. He visited her mother since she made fun of his hobbies. Howard pulls out a ventriloquist dummy she used in her beauty pageants she entered as a child. Bernadette introduces Howard to “Tammy Jo St. Cloud”, who starts to make fun of Howard who quickly escapes from the kitchen.
In the street Sheldon is seen walking on stilts and then, he wakes up in bed with Amy.
- Guest starring:
- Teleplay: Dave Goetsch, Eric Kaplan & Jim Reynolds
- Story: Steve Holland, Tara Hernandez & Jeremy Howe
- Title Reference: Sheldon is trying to make his mind sharper.
- Taping date: April 4, 2017
- This episode was watched by 12.52 million people with a rating of 2.6 (adults 18-49).
- Total viewers including DVR users 16.23 million.
- The Big Bang Theory was ranked #x for the week ending xx April 2017.
- This episode aired in Canada on April 27, 2017.
- Chuck Lorre's vanity card .
- Caroline Preece at Den of Geek! - I like how the show is following Penny’s career path at an almost realistic way, having her grow tired of the grind off-screen but not ignoring it completely. If nothing else, it’s more interesting than her trying and failing to be an actress but, as fun as Zach always is to have around, I’m not crazy about it being used to briefly introduce a love triangle. Perhaps this will be dropped given that Zach’s unseen fiance vetoed the idea, but it’s been obvious for a good long while that the show needs to do something new with Leonard and Penny. A competitor for her affections is an obvious route (and we know this show loves its obvious routes) to go down and would tie in with the idea that, now that they’re married, Leonard isn’t trying as hard in the relationship. Howard and Bernadette get a very small part of the episode with the latter making fun of her husband for being into juggling when he was younger. To get his own back Howard digs for dirt on her from Bernadette’s mother, and finds out that she used to be into ventriloquist dummies. The dummy in question - Tammy-Jo St Cloud - is terrifying, and the scene should be prefaced by a trigger warning for dummy-phobes. 
- IMDb user reviews
- Zack Johnson returns in this episode; his most recent episode was "The Fermentation Bifurcation".
- Also, this is the second 22nd episode that Zack appears in after the previous season's "The Fermentation Bifurcation" (S9E22).
- Raj says he never learnt Hindi, yet he was shown to speak Hindi in "The Vengeance Formulation" and "The Psychic Vortex".
- Siri was last prominently featured in "The Beta Test Initiation". Zack incorrectly refers to it as "Sara".
- Sheldon's struggle with memory issues continues from "The Recollection Dissipation".
- Zack is revealed to be engaged.
- Leonard: We're pinned down!
- Howard: We can't get through!
- Raj: Sheldon, get over here and help!
- Sheldon: OK, one second.
- Leonard: Sheldon, why are you jumping up and down?
- Sheldon: I'm trying to shoot!
- Howard: Then use the 'Shoot' button not the 'Wonderful-thing-about-Tiggers' button!
- Leonard: Aaaw.
- Raj: That's it. We're dead.
- Howard: Challenge them again.
- Leonard: Doing it right now. They can't; there's an important Little League game :
- Howard: No wonder they beat us; they're jocks.
- Zack: What are the odds of running into you here?
- Penny: Well, it's a bar, so pretty good.
- Amy: What happened to learning the unicycle?
- Sheldon: I stopped that; it was dumb. Uni-, bi-, tri-, menstrual; all cycles are dumb.
- Amy: [Sheldon has just stormed out] His mother warned me. Everybody warned me. Actually, * he* warned me.
- Sheldon: [walking along the sidewalk on very tall stilts] I'm doing it. I'm doing it. I'm tall, and I'm doing it. [wakes up in bed] Aw, man.