(or "You know you're a tired mommy when...")
Part 1: It takes you all day to realize you've had your shirt on backwards.
Part 2: Your reaction to this realization is positive, because a.) that means you at least got out of your jammies, and b.) you think "Yipee! Now I can wear this shirt again before washing it because the spit-up is on the back side!"
Yes, it's sadly but truly based on a recent experience.