My mother Kathy has a long-standing joke.

I call her on the phone. She says, “Who’s this?”  I say, “It’s your daughter.” She says, “I don’t have a daughter.”

Same thing when I show up at the front door. “Who’s there?” “Your daughter.” “I don’t have a daughter.”

She’s done it for years. And I’ve always liked the joke.

She’s distilled the joke recently. She sees an old friend or someone in the family and she simply asks, “Who are you?” The person says, “I’m so-and-so. Your daughter’s friend.” She says, “I know that. I was just kidding.”

Today during Mother’s Day brunch, Kathy asked me, “Now, who are you?” I responded, “I’m Deirdre. Your daughter.”  She laughed, “I know that. I was just kidding.”

But the truth is, she didn’t know that. She wasn’t kidding.

For the first time ever, my mom did not recognize me.

She’s 74 and grappling with increasingly advanced Alzheimer’s. It’s becoming more and more difficult for her to mask the disease. Thank god she set up her joke ages ago, because it softened the impact of that question today, “Who are you?” I was able to hold it together and tell her, “I’m your daughter.”

But what I should have answered was, “I’m your daughter. And I love you. And I thank you for all the sacrifices you made over the years for me and our family. I know it hasn’t always been easy and the challenges of married life and motherhood were often defeating, even crushing. But I always knew you loved me – and that gave me the confidence to believe in myself, to take life by the balls, and to try to be a half-way decent mother myself.”

I’ll tell her tomorrow.

But first, I’ll introduce myself.

(Pictured above: Some of my favorite moms and brood, Kathy with my brothers Sam and Don and myself, Andrea and Sofie, Libby and Laura – oh, and me and Rose!)