It's not uncommon for us to run into friends that we haven't seen in a month or two. Sometimes they've been overseas or visiting grandparents for extended periods of time. Other times naps or classes switched up their schedules. I always enjoy seeing how their little ones have changed when they reemerge... are they more adventurous crawlers, walkers, talkers?
When you are with your child almost every day, it's not so easy to notice these subtle changes. It's clear when little one switches from crawling to walking, but not so clear how he went from unsteady steps to almost running. Similarly, you might not notice a growth spurt until you see your little one running at the park with pants that no longer cover his ankles.
With my own son, I've noticed the biggest changes when we travel to zoos, museums, or other attractions that we only make our way to once a month or so. Which rides does he enjoy this time that weren't a hit last time? Will he want to feed the goats? Can he say any of the animals' names? I'm constantly surprised by how different these outings are from month to month. When we go on these infrequent outings, they highlight many of the more subtle skills that my son has slowly been accumulating week after week.
With the children in your life, when do you notice these leaps? When visiting relatives? watching home videos? looking at old photos?