I definitely remember those days. Both our kids are in university now and the part of the chart that spoke to me was seeing that steep drop off when the kids reach a certain age. It was a big change when the kids started high school and all of their sports and activities were based around the school instead of parent volunteers.
It is fine now, and it is great to hear what the kids are learning in physics and math, and even cooler when they ask the old man for advice on a programming assignment. I would really love to have a couple of hours back though when we were all doing Lego robotics together. I miss those days.