I'm seeing quite a bit of comment about this, so I want to make a couple of points.

I'm not owed eternal agreement from any actor who once played a character I created. The idea is as ludicrous as me checking with the boss I had when I was twenty-one for what opinions I should hold these days.

Emma Watson and her co-stars have every right to embrace gender identity ideology. Such beliefs are legally protected, and I wouldn't want to see any of them threatened with loss of work, or violence, or death, because of them.

However, Emma and Dan in particular have both made it clear over the last few years that they think our former professional association gives them a particular right - nay, obligation - to critique me and my views in public. Years after they finished acting in Potter, they continue to assume the role of de facto spokespeople for the world I created.

When you've known people since they were ten years old it's hard to shake a certain protectiveness. Until quite recently, I hadn't managed to throw off the memory of children who needed to be gently coaxed through their dialogue in a big scary film studio. For the past few years, I've repeatedly declined invitations from journalists to comment on Emma specifically, most notably on the Witch Trials of JK Rowling. Ironically, I told the producers that I didn't want her to be hounded as the result of anything I said.

The television presenter in the attached clip highlights Emma's 'all witches' speech, and in truth, that was a turning point for me, but it had a postscript that hurt far more than the speech itself. Emma asked someone to pass on a handwritten note from her to me, which contained the single sentence 'I'm so sorry for what you're going through' (she has my phone number). This was back when the death, rape and torture threats against me were at their peak, at a time when my personal security measures had had to be tightened considerably and I was constantly worried for my family's safety. Emma had just publicly poured more petrol on the flames, yet thought a one line expression of concern from her would reassure me of her fundamental sympathy and kindness.

Like other people who've never experienced adult life uncushioned by wealth and fame, Emma has so little experience of real life she's ignorant of how ignorant she is. She'll never need a homeless shelter. She's never going to be placed on a mixed sex public hospital ward. I'd be astounded if she's been in a high street changing room since childhood. Her 'public bathroom' is single occupancy and comes with a security man standing guard outside the door. Has she had to strip off in a newly mixed-sex changing room at a council-run swimming pool? Is she ever likely to need a state-run rape crisis centre that refuses to guarantee an all-female service? To find herself sharing a prison cell with a male rapist who's identified into the women's prison?

I wasn't a multimillionaire at fourteen. I lived in poverty while writing the book that made Emma famous. I therefore understand from my own life experience what the trashing of women's rights in which Emma has so enthusiastically participated means to women and girls without her privileges.

The greatest irony here is that, had Emma not decided in her most recent interview to declare that she loves and treasures me - a change of tack I suspect she's adopted because she's noticed full-throated condemnation of me is no longer quite as fashionable as it was - I might never have been this honest.

Adults can't expect to cosy up to an activist movement that regularly calls for a friend's assassination, then assert their right to the former friend's love, as though the friend was in fact their mother. Emma is rightly free to disagree with me and indeed to discuss her feelings about me in public - but I have the same right, and I've finally decided to exercise it.