YOU can argue about the value of the past.

Is it only the present and the future that matter or is the past vital as an anchor, holding your place in the here and now?

I used to love when I was little and old neighbours or old friends of my mother, newly met, would say: "I remember you when you were a baby." It gave me a sense of my own history and of change.

My Granny Porteous has just had her 100th birthday (today she is 100 and one day) and I think about everything she has seen: toddling during the First World War, the wife of an airman during the Second World War, a young mum in the 50s, and so on until now. I am sure she remembers me as a baby, and my cousins and my cousins' children.

Granny Porteous is a proper granny of the type just about to go extinct; not one of the new breed of grans who keep their own hair colour and faff about on iPads and go internet dating. No, a real gran, equipped with survival skills gained running a home during rationing and regular blackouts. One who can make you feel grateful for what you have because, "in my day ... "

A real gran has a perm, preferably grey, and wears pleated skirts. She can knit, she can bake and she can entertain you with naught but a wooden peg and some leftover wool. She can probably hold her own on the piano, knows a scone recipe by heart and the hymns just by the number.

Her home is a sanctuary - there is always tea, cake in the tin and an electric fire burning. She will listen to you talk about yourself for hours before briskly, yet sympathetically, nudging you to get a grip of yourself. She is convinced you are the best thing ever. You feel like the best thing ever, taking tea and helping yourself to a slice of cake from the tin. Both are served on fine bone china.

A proper gran is old but somehow ageless. She can tell you about the war and the 1970s and when your parents met and the night you were born. She is very likely a game old bird. She will enjoy a tot of sherry but balk at the notion of a lady drinking beer. She is to be learned from. Her decisions have helped lead to this point now, where you are.

I feel sad for children now who will never know the comfort of a real granny, with bosoms built for comfort and backbones of steel, ladies who have endured a lifetime of change and kept their sense of mischief.

Happy birthday, Granny P, with all my love.