Adult Sheldon: Like a virus, heartbreak can also spread. Once it does, it's hard to contain. In some cases you can try to reboot and start over. But it makes you appreciate those early days, when your hard drive was clean... and the world was full of possibility.

Adult Sheldon: I didn't realize until years later that my father was only asking questions about lightning and thunder to cheer me up. In fact, he would often pretend to be dumb just to make me feel better.

Adult Sheldon: My father didn't always get the credit he deserved. The advice he gave me actually worked out pretty well. Of course, I never told him.
George Sr.: Talked to Billy.
Missy: Why would you do that?
George Sr.: No, it was good.
Missy: Stay out of my life.
Adult Sheldon: He may not have been the world's greatest dad. But maybe we weren't the world's greatest kids.

Adult Sheldon: Visiting Tam's house for the first time was an emotional roller coaster.
For example, it's traditional in Vietnamese homes to have gruesome religious iconography near the entrance. I did not like that.
However, it's also customary to not wear shoes around the house for sanitary reasons. I did like that.
Interestingly, one of the main ingredients in Vietnamese cooking is an extremely pungent condiment known as fish sauce. I did not like that.
But before every meal, it's common for everyone to wash their hands and face. I did like that.
Forks are not customary in a Vietnamese household. I did not like that.
And instead of napkins, there was one towel for everyone to share at the table. Seriously, what are they thinking?

Meemaw: Well, let's get into it. What happened? If it's another woman, she's a tramp, and you're way prettier.
Brenda Sparks: No. Although sometimes I wish there was. Then I'd have someone to be mad at other than myself.
Meemaw: And here I thought this one was gonna be the sad sack.
Mary: Mom, that is enough.
Meemaw: Oh, there's my little killjoy. [both laughing]

Adult Sheldon: As long as humans have been on Earth, they've had to contend with viruses. And as long as I've been on Earth, I've come up with fun ways to avoid them.
[flashback:]
Dr. Linkletter: I've heard so much about you. [offers hand]
Sheldon: Apparently not how I feel about shaking hands.
Adult Sheldon: I wear personal protective equipment...
[flashback to Sheldon putting on mittens at the dinner table]
[flashback to Sheldon wearing an astronaut suit in his bubble:]
Mary: You come here right this instant.
Adult Sheldon: ...and I was social distancing before it was cool. But in the early '90s, a new type of virus became prevalent. One that no amount of hand-washing could stop. A computer virus.
Sheldon: Oh, no.
Adult Sheldon: But let's back up and begin this story in a simpler time, before an insidious infection had upended my life.

Sheldon: Ooh, there's a computer game called Railroad Kingdom. Can we get it?
Mary: How much is it?
Sheldon: $49.95.
Missy: Are you crazy?
Mary: I'll handle this. I am not paying that much for a game.
Sheldon: It's not just a game. It's a cutting-edge simulation teaching business skills in the golden age of railroads.
Mary: It doesn't matter.
Sheldon: But what if I end up running a railroad one day and don't have the necessary business skills?
Missy: I think I nailed it with, "Are you crazy?"