My father was giddy with excitement at the arrival of my daughter Matilda, 12 months ago. He moved into our tiny flat and slept on the uncomfortable sofa under a thin duvet for three weeks, so he could be around to help at night.
When I was at my most frazzled and tired but his granddaughter needed winding and settling, he was there. The night watchman with a big heart, bursting with love for this tiny person.
The change in my sensible and strict father wasn't a shock this time round but when my son was born two years before Matilda's arrival, he surprised us all by lovingly taking up the role of active, engaged grandparent. He left his city suits and stiff upper lip at home, and appeared at the hospital, cooing and singing lullabies, clearly smitten.
He even remained calm when I breastfed in front of him (under my modesty cloak of course) despite normally being a complete prude, and became my taxi driver - taking me to my check-ups when my cervix and nipples were discussed at length - without complaining (or blushing).
He didn't care - it was all for the good of his grandchild. He comes from the Michael Middleton and Prince Charles generation of loving Gramps, determined not to miss out on this magical family time like his father's generation were expected to.
"I get to enjoy being around babies without all the financial worry and general stress this time round," he confessed while gazing adoringly at Matilda. "Being a granddad is the fun bit and I get to hand them back."
"After the mother and father, it's normally the grandma who gets the most attention when a new baby is born - everyone assumes they're helping the most, the happiest.
"But the modern man in his 40s, 50s and 60s can be a metrosexual softie and nowhere is that more apparent than when his child has a child," explains family psychologist Dr Brian Beckham.
"Times have changed for them since they were fathers. They probably have more disposable income, more free time, and less social hang-ups about showing affection."
Countless friends have told me how their fathers, who were disinterested or distant with them when they grew up, have turned into balls of mushy love when faced with the next generation down.
One friend's dad started growing a beard in August so he could play the perfect Santa when his grandkids came for Christmas; one went to a studio to record him singing songs his grandparents sang to him as a child so they wouldn't forget his voice when they moved to Dubai; another turned his English country garden into an Alice in Wonderland themed hideaway for his four granddaughters - and didn't even mind partaking in constant tea parties on tiny chairs out there.
Can you imagine this happening even 20 years ago? Never!
Celebrities are of course getting in on the trend too. The famous men we grew up with are now doting grandpas ... And it brings out a whole softer side to them. Pierce Brosnan (who's known as Pappy), Jim Carrey, Cee Lo Green, Steven Tyler, Rod Stewart and Kiefer Sutherland have all talked about loving being grandfathers - and even Hollywood wild man Charlie Sheen seems to have calmed down since becoming a granddad recently.
"A granddad's importance to a child can never be overstated," says Dr Beckham. "They are the living history and tradition of the family, with the patience only time can give. They can provide the child with the love of a parent with little to none of the expectations.
"The grandparents are normally settled in their lives so can enjoy the child - and the child can enjoy them - with little of the pressures of life that mum and dad have to deal with. Also because the grandpa has already been through the process of raising children, he knows what is coming and how to best deal with it, so emotions are less fraught."
So as Prince Charles and Michael Middleton eagerly await their second royal grand-baby, make the most of your dad or father-in-law, waiting in the wings with the wet wipes and a melting heart. These days, granddad rocks - the cradle and in general.