I did not mean to listen: but when someone talks loudly across cubicles...
.. well when someone talks loudly across cubicles, you can't help but overhear.
And when someone starts with "I am not being cheap, but..." - well then you know they are being cheap.
"..but, why is this flight so expensive? Because it is direct Newark to Toronto? Can you make the meetings if you fly through DC? Or Chicago, that would be best."