
The guy's a genius. Maybe you weren't
CHALLENGING enough for him.
The Big Bang Theory Season 6, Episode 6

- Just as CHALLENGING as you?
- Yeah...
The Big Bang Theory Season 10, Episode 5

It's like me CHALLENGING you
to a sexy pants contest.
The Big Bang Theory Season 8, Episode 19

but the truth is,
Amy is just as CHALLENGING.
The Big Bang Theory Season 10, Episode 5

Oh, we'll make the puzzles
extremely CHALLENGING
The Big Bang Theory Season 9, Episode 8