I am standing in the foyer of a UK theatre, saying goodnight to 400 mums and dads after giving my talk about girls.
The parents all seem so young to me now, and I feel a grandfatherly warmth towards them that makes my work very easy to do.
Some share a hug, some have a book to be signed, some just smile warmly and say thanks.
I have the best job in the world, really.
Then along comes an older man, bearded, with thick glasses.
He stands very close. “Feminism is a plot to destroy society!” he shouts.
He raises his voice to address the whole crowd.
I am floored as to what to say, but English people know how to deal with eccentricity, they give him back good measure, and he storms off into the night.
Feminism did cause great insecurity in a generation of men, thankfully now a dying breed.
Most of us woke up to, or really never had a problem with the idea that women and girls should have the same opportunities and be valued as highly as men.
And if we had daughters or partners that we loved, then feminism became an article of faith.
Girls need feminism, and in fact we need to ramp it up to meet a whole new slew of problems girls are having.
Your daughter, whether she is eight or eighteen, will be prone to taking many things personally.
Worrying about not looking like the girls in the magazines or on the internet.
Feeling harassed by boys, or ogled by men in the street or on buses.
Many primary school girls now report horrible experiences of being leered at by grown men, licking their lips, staring up and down their bodies.
The pressures to be perfect in schoolwork, in sport, in social standing on social media.
If your daughter learns that she is part of something big and inspiring, it will help her.
That it took a century of struggle - that even the right to vote was fought for in bloody street battles with police, and prison sentences and hunger strikes.
That equal pay, the right not to be raped by your husband, the right to divorce, and safety from beating are all recent things.
The right to do the same jobs as men, and get the same pay.
To get maternity leave.
Today the fight goes on against child prostitution and sex trafficking, violent pornography, bullying and date rape.
There are millions of people working and uniting against these things, and she can join this fight.
When she knows that, she will feel not frightened, but strong. Not scared, but angry. And that will help her.
Men have their problems too.
I have worked on those for almost 40 years.
We need to help boys and men to be in touch with their emotions, able to express them, be vulnerable and be more free and alive.
To have real friends and find support for living our often difficult lives.
Then we won’t be threatened by the joy and aliveness of women, or feel a need to shout at people in theatres!
Our families will thrive and we’ll be comfortable in our skins. Then women can be comfortable and safe in theirs.
Steve Biddulph is the author of the Ten Things Girls Need Most, Manhood, and Raising Boys.