I haven't seen him this stuck since he
tried to figure out the third Matrix movie.
The Big Bang Theory Season 3, Episode 14
the calculation
of nuclear MATRIX elements.
The Big Bang Theory Season 7, Episode 20
You can see the MATRIX, can't you?
The Big Bang Theory Season 1, Episode 12
I'm in the MATRIX, Leonard;
I see everything.
The Big Bang Theory Season 5, Episode 10