Nickie Muir: Out of the mouth of Rainbow Trout

Hitting the halfway mark of my fifth decade, I feel I should have a lot more answers to the meaning of life than seem apparent to me right now. Ali said if you thought the same at 50 as you did at 20, you'd basically wasted 30 years of your life. I wonder how much I've wasted.

"It's lucky you didn't have a kid when you were 18 - she would have been called Rainbow Trout or Lotus Frond or something," said Dad.

He felt, wrongly, as it happens, that I had grown more mature and was now a much better mum than I would have been all that time ago. He also likes to remind me of those hippie years when I wore saffron trousers and lectured people about all the souls they were eating in the form of meat. I once told him this karmic luggage would haunt him on his deathbed, during one of his 'home kill' carve-ups in the kitchen. That was before I washed up in Argentina and became corrupted into a profligate carnivore.

If I met my 20-year-old self, I think I'd be bored senseless by the overkill with all things natural and point out that heroin and homicide were historically natural, which didn't make them intrinsically good to indulge in.

Thankfully, we never get to suffer the younger versions of ourselves - which is why we are sent children so they can do it back to us.

"Mum," said the small person. "You just said the F word and ACTUALLY people up to my age shouldn't even have ever heard of that word."

If Dad had wanted a score card on optimal parenting, he should have asked my daughter.

"Mum," she said later, clearly thinking of my near half-century on Earth, "what was it like in the olden days?"

This is not the kind of question a woman relishes. I consider some of her Enid Blyton favourites, some of which had been mine, in which the children get to go to some farm because "Mummy must accompany Daddy to America for six months". I tell her that in the olden days mums were allowed to give their kids to someone else if they didn't like them. She finds this doubtful. Later, I notice her doing tricky arithmetic on her fingers. "What are you doing?" I ask. "Working out how many more years you've probably got to live," she says.

This birthday is really not proving to be a celebratory flag-filled borderline in the country of my life. At the vege market, deep in conversation over the coming local elections with a producer who is threatening to boycott them, she tells me: "Mum. The market is for buying vegetables. Not for talking about politics."

I wonder if she'd be so pragmatic if I'd called her Rainbow Trout. Thirty years ago, I would have had to tell her all the reasons why she was wrong.

Instead, I shrug and head for celebratory coffee and coconut macaroons and am thankful that there is something I have learned after all.