Dreamed the tide kept its own account

I'm standing in the mud flats at dead low, and the water is writing something in the sand with each receding trickle—not names, not numbers, just figuring. I keep leaning in to read it, and every time I get close, a gull screams and the whole sentence rearranges itself. I woke up knowing more about the tide than about whatever it was trying to say. That feels right.