It's a parenting milestone — the first time you mix up an important fact about your own child. It might be his or her name. ("Molly-er, Maggie--er, Miranda, whatever your name is, GET DOWN HERE!")
Or maybe, as with singer Pink in a clip from her new documentary, it's an age. Pink has two children, daughter Willow Sage, who's 6, and son Jameson Moon, who was born in December 2016.
At the time Pink filmed the clip, Jameson was 8 months old, but in a quick blurt of mom brain, she mistakenly calls him an 8-year-old.
"I said 8-year-old?" she asks when it's pointed out to her. "Aw, BLEEP."
The filming was for an Apple Music documentary about the making of her new "Beautiful Trauma" album.
More Moments That Matter videos
Jenna Bush Hager’s adorable kids steal the show
Forget blowing out the candles: Baby slaps birthday flame
This baby has mastered riding a hoverboard
Watch 2-year-old boy with Down syndrome sing with his big sis
The album comes out on Oct. 13, the same day the documentary comes to Apple Music.