Young Sheldon, Season 1

[First lines of the series]

Adult Sheldon:
"I've always loved trains. In fact, if my career in theoretical physics hadn't worked out, my backup plan was to become a professional ticket taker. Or hobo. And when I figured out that trains allowed me to prove Newton's first law... An object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force... I felt like Neil Armstrong on the moon, alone and happy."

Mary Cooper:
Shelly, dinner's ready!

Adult Sheldon:
"I don't care how dimwitted you are. Scientific principles have to make you smile. Of course, nobody I knew in East Texas in 1989 cared about Newtonian physics. The only Newtons they cared about were Wayne and Fig."

Missy Cooper:
Sheldon, if you don't get in here, I'm gonna lick your toothbrush.

Sheldon Cooper:
Coming!

Adult Sheldon:
"That's my sister. And she's done it before."

George Cooper Sr.:
Hey, what the hell are you doing out there?

Mary Cooper:
George, language.

George Cooper Sr.:
What language? So?

Sheldon Cooper:
I was exploring dimensional kinematics.

Georgie Cooper:
Admit it, he's adopted.

Sheldon Cooper:
How can I be adopted when I have a twin sister? Think, monkey, think.

Mary Cooper:
That's enough. No one's adopted.

Missy Cooper:
I wish I was.

Mary Cooper:
That can still be arranged.