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.