Mary: I'm reading this book about mental problems, and I'm worried it sounds like Sheldon.
George Sr.: Well, stop reading the book.
Mary: Shelly and Dr. Sturgis have a lot in common, and look what happened.
George Sr.: What, you mean like how he went to-
Adult Sheldon: As a society, we've made strides in how we discuss psychological issues. 30 years ago in East Texas, let's just say we hadn't.
George Sr.: cuckoo, cuckoo. [blubbers]

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?

Mary: I was just letting you know that if you were having any problems you could come to me with them.
Sheldon: You think I have mental problems?
Mary: Well, not problems. I'm just worried about your future, and when I see you moving subatomic particles around in the air, that makes-
Sheldon: Subatomic particles are real! You talk to an invisible man in the sky who grants wishes. If anyone's mental, it's you.

Sheldon: [to Mary] I am behaving no differently than I ever have. Why are you suddenly so worried about me?
Dr. Goetsch: That is a valid question. Has anything changed recently?
Sheldon: Maybe it's hormonal. When does menopause typically begin?
Mary: It is not my hormones.
Sheldon: Well, it certainly isn't mine. I'm showing no signs of puberty.

Sheldon: Mother?
Mary: Yes?
Sheldon: Is it okay if I use a knife to butter my toast, or are you worried I'll do something crazy with it?
Mary: You can butter your own toast.
Sheldon: Oh, good. You see the toast, too. I was afraid I was imagining it.