A-ha!
The Big Bang Theory Season 9, Episode 13
No, I think it's stupid.
Aha!
The Big Bang Theory Season 7, Episode 16
Aha! So I am working with you?
The Big Bang Theory Season 3, Episode 4
Aha!
The Big Bang Theory Season 7, Episode 3
A-ha! You are upset.
The Big Bang Theory Season 10, Episode 20