Monk, Season 3

[Monk and Natalie have brought Tommy along as they stake out the Carlyles]

Natalie:
Oh, my God! What is this? Why is he wearing a helmet?

Monk:
To protect his head.

Natalie:
It must be so uncomfortable.

Monk:
Oh, he'll get used to it. I used to wear one all the time.

Natalie:
Your parents made you wear a helmet?

Monk:
No.