They say you should never go back. But they're wrong. I didn't know this when I'd said 'yes' to an old girls' reunion.

Someone had the idea of getting us all together, 25 years on. Right up to the day I'd wondered if it would all be a ghastly mistake.

Although lunch was the social highlight, I decided to turn up for the old girls' association AGM where the head was to speak. I didn't know her and I reckoned it would give a good feel of the school's current ethos.

It did. As you'd expect of a smallish, Home Counties independent girls' school, she was elegant, competent, mistress of her art and of the occasion.

Like many heads, she revelled in the examination league tables, which confirmed trends that girls achieve a better performance at single-sex schools than at mixed ones. She recounted A-level and GCSE successes with relish.

I sat up, though, when she told a little anecdote about two social services inspectors who had visited the school to see that it complied with the provisions of the Children Act.

They had stayed in one of the boarding houses and breakfasted with the girls. They reported that the girls appeared happy and well looked after.

The head smiled condescendingly. 'One of the girls came up afterwards and said: 'They weren't very intelligent men, were they? They asked if we wouldn't prefer breakfast any time between seven o'clock and 8.30.

' 'We told them we'd just never get up if it wasn't at a set time and how would the staff know if we'd eaten anything?' '

The head had told this story to great effect at the annual speech day. She was again sure of her audience. Knowing grins flashed around the room. Shoulders heaved with mirth under designer suits and Laura Ashley frocks.

I was appalled. Here was a school head, not simply deriding two men doing an important job, but encouraging pupils and parents to share the same patronising attitude.

Perhaps the inspectors did ask facile questions - but weren't they knowingly designed to elicit revealing answers?

This school might not be a Dotheboys Hall, but if I were a parent, I'd want to be sure of it. I'd also appreciate that there are plenty of schools where the children's welfare is not so assured.

Instead of sneering at state interventionism, I'd have preferred the head to speak approvingly of safeguards and standards and to teach her girls accordingly.

Pats on the back, certainly, when hurdles are easily cleared, but not this superior dismissal of legislation for which other children are deeply grateful.

It shook me rather. I was grateful for my good academic education but I had forgotten this smug self-righteousness and conformity of view which made the head's story acceptable to her audience.

In many ways girls' schools do foster social awareness and a public duty and encourage pupils to do charity work.

Their great weakness is a self-perpetuating conservatism, probably with both a big and small 'c', which urges conformity and stifles independent thought.

I was reminded forcibly of this when I met my own old headmistress. She taught me history and to stand up straight. We had crossed swords before.

I had been ringleader of a sixth-form revolt, spokeswoman for a groundswell of dissatisfaction with petty rules, old-fashioned attitudes and a refusal to treat us as young adults. The rebellion was not well received, although it bore fruit in a new school council, a common room, and the lifting of some restrictions.

But what was meant as constructive criticism was taken as a personal insult. How dare I suggest she had got it wrong]

These reflections came flooding back when I greeted her, a frail eighty-something now. What got my goat anew was her comment: 'It's taken a long time for this one . . . .'

To go back, certainly. But she meant more than that. She meant to return to the fold, to acquiesce, to see that after all the school's and her values were right.

Over the years I'd come to think my unhappy memories were related to the turbulent times. It was 1968, after all. Perhaps I was simply a normal adolescent reacting to authority.

I'd been right to go back. It stripped away all the sentiment that had accrued. I was angry again and disappointed that, deep down, nothing had really changed.

The old girls' president told us: 'Don't just talk of your old school. Name it] Speak of it with pride]'

I can't do that. Academically it did me proud and continues to turn out well-qualified girls. But a school should do more than that.