Your childless friends are incapable of understanding why you're suddenly canceling plans or showing up 30 minutes late. Why you can't accept a phone call as planned. Why you just zoned out mid-conversation.
Forgive them for their inability to understand the chaos of your new role and your shifting hormonal state, and know that they still love and support you, even if they don't quite understand. You likely did not grasp the nuances of new motherhood before you entered into it, so give your childless friends the same grace you want for yourself. The friendships that are strong at their roots will be the ones that aren't blown away by the windstorm of the postpartum period.