...because he said
it was a THEORETICAL nut conflict.
The Big Bang Theory Season 8, Episode 21
Is it maybe because, like Sheldon's work,
your sex life is also THEORETICAL?
The Big Bang Theory Season 6, Episode 9
as a THEORETICAL
physicist,
The Big Bang Theory Season 7, Episode 20
Now to tell you about
the Theoretical Physics Department...
The Big Bang Theory Season 2, Episode 6
You're summa cum laude in THEORETICAL
physics from Stanford University.
The Big Bang Theory Season 6, Episode 3