The Kids Getting Older Younger (KGOY) phenomenon and what Christian parents need to do about it

My youngest is eight-years-old and I find myself in a slight panic that these years are all going by so fast. With my eldest about to go to Sixth Form, I feel the ticking of the clock over my kids’ childhood, the years rushing by with alarming alacrity. I regularly look at the little hand that, I’m grateful, still holds mine as we walk and I want to squeeze it and not let go. How can my youngest be eight?!