Mother's Selective Memory Loss

Mother rings. I can tell from the first word she utters that she is in One of Her Moods.
"Hello."
That's all it takes. One tight-lipped, two-syllable word and my hackles are already up.
"Hello," I say, forcing a bit of bright-and-breeziness into my voice.
"I hear you're going on holiday," she says. She says it as if what she actually means is: "I hear you've just murdered a small child and eaten its pet kitten for breakfast."
"Ye-ess," I say. "I told you at Christmas that we were going skiing at half term."
"No you didn't."
I breathe in deeply and let the air out slowly through inflated cheeks. "I did," I say. "I also told you last week when you told me you couldn't speak to me as you were watching University Challenge."
"Nonsense. And how am I supposed to know when half term is anyway? You never tell me anything about your life and I never speak to the grandchildren."
"O-kaaay," I say. "Well, it's half term this weekend and we are going skiing."
"Stupid idea. You'll only break something."
"Probably. How are you?"
"Y'father's leg's playing up but I've had a lovely time playing bridge and going to a birthday party and we are going to Cambridge this weekend. We wanted to go and spend half term with y'sister, but she--"
"I thought you didn't know when half term was?" I say.
"Er, well, how am I supposed to know that your half term is the same as their half term? Anyway, that's not the point. What should I get y'daughter for her birthday. That's over half term, isn't it?" she says in an almost-change-of-subject.
I bite the inside of my cheeks and punch a poor unsuspecting cushion very hard indeed. The dog scuttles to take refuge in her basket in case she is next in line. "Yes, but you've already got her something," I remind Mother. "You bought her a jacket for Christmas and said that it would have to do for her birthday as well."
"I did not."
"You did--"
"Well, I want to be a lovely grandma who my grandchildren think fondly of, so I want to get her another present. And by the way, I hope she thinks of me every time she wears that jacket."
"I'm sure she does, Mother," I say.
Even the dog is rolling her eyes.
I replace the receiver with quiet deliberation and then go into the larder.
Husband comes home minutes later to meet me coming out of the larder, red faced, fists clenched, eyes wild.
"What on earth's the matter?" he asks.
"I've been swearing in the larder," I say.
"Swearing in the larder is still swearing," he says, with a raise of the eyebrows.
"I know," I say. "And I'll be going back in there in a minute if you don't stop looking at me like that."
Husband sighs. "The holiday couldn't come a moment sooner," he says, shaking his head at me sorrowfully.