
Okay, the simplest EXPLANATION
is usually the right one.
The Big Bang Theory Season 10, Episode 24

...but there is a reasonable EXPLANATION.
While I slept in my sleeper car...
The Big Bang Theory Season 8, Episode 1

The only logical EXPLANATION
is that this is a dream.
The Big Bang Theory Season 5, Episode 20

I did say that was
one possible EXPLANATION.
The Big Bang Theory Season 12, Episode 20

I just gave you a reasonable EXPLANATION.
The Big Bang Theory Season 1, Episode 2