Many, no doubt, will agree with him about the ubiquitous selfie. Since its arrival in popular culture in 2013, it has come to dominate social media. It started off slowly, a trickle of pictures on Twitter, Instagram and Facebook, but within months selfies were everywhere. Last Christmas' must-have gift was the selfie stick, a lengthening device to take better pictures that connects to your phone via Bluetooth.
READ MORE: What your selfie says about you
Sometime the selfie can be put to good use, as in the 2014 #nomakeupselfie, where women took pictures of their bare faces and donated money to Cancer Research (more than pounds 8 million was raised in Britain in six days). But mostly selfies are pure vanity projects, a way to brag: "look how good I look", or "look who I met", or "here's me and [celebrity xxx]".
No one epitomises this more than Kardashian, the Queen of the Selfie, who alongside the sexualised selfies she posts to her 29.4 million followers on Instagram, also creates Selfie Books - whole bound albums of pictures of herself - for her husband, rapper Kanye West. She has just released her first published book, Selfish, which features no less than 352 of her favourite pictures of herself.
I have some sympathy with Kim because I, too, was a selfie addict although I'm now in recovery. I know just how hard it is to kick the habit.
My own addiction started innocently enough, I wanted to put pictures on a blog. But then, I noticed how much better I looked with a flattering filter - the transfer filter. And then how much better I looked when I used the editing device picMonkey - whiter teeth, smoother skin and, my favourite, the liquify tool which can make you appear thinner! I became enamoured, dependent and eventually addicted. Wherever I went, a selfie was required. I was obsessed. And then I discovered the selfie stick. What greater gift to myself could there be? We were inseparable, me and the stick. But then, well, things came to a head. When, at Christmas, while perfecting a shot from behind - fishing-rod style selfie - I accidentally hit my 91-year-old granny on the head. Something had to give - and I gave away my selfie stick.
But I'm a twentysomething who recognised that my habit had got out of control. Problems arise - and this is where Prince Harry was offering sound advice - when it is youngsters or teenagers who go selfie-mad. "Kids are hardwired to copy adults," explains Emily Lovegrove, a psychologist who specialises in bullying, "and when they see - in their eyes - successful adults, they want to ape their behaviour." And with more children having mobile devices it's getting harder to monitor both the selfie-taking and where the selfies are being distributed.
It is something that preoccupies the Mumsnet forum, where many discussions have been had on how to wean children off the selfie habit. "The trick is to encourage your children to see smartphones as brilliant tools, not life-support systems," says Justine Roberts, co-founder of Mumsnet. "Sharing silly selfies with a closed group of friends is one thing. Sharing compromising photos with, potentially, the entire world - including prospective university entrance tutors, employers and your grandparents - is another." Roberts suggests that parents need to lead by example and put their phones out of sight and out of mind. "Parents need to try not to be hypocrites about it," she says. "Lecturing your child about mobile addiction with your own phone glued to your hand may not be a very effective approach."
Certainly, parents must take the lead in initiating family digital detox - and there's no time like the weekend. Experts suggest encouraging kids to take photographs of other things, rather than themselves. Trying to get the best angles or look the best is not good for confidence or self-esteem.
Group pictures are fine, as are pictures with friends, but it's not healthy to take so many pictures of yourself.
Prince Harry may have done parents and children a favour, then. It's vital that we - children and adults - learn to respect others. Not just our selfies.
- Canvas, Telegraph