Kathleen Madigan learned more about her parents during a recent two-week visit with them in the Midwest, and she shared her findings on¬†Friday night’s Late Show with David Letterman.

For one thing, Madigan is amazed at the U.S. Postal Service for raising the price of stamps — but not for the reason you’re likely amazed. Then again, she might have just taken another pill from her mother. It seemed like a good idea at the time.

Roll the clip!

Her third hour-long special, Madigan Again, is available now on Netflix. A CD/DVD version will be available Oct. 8.