Life's gracefulness lost on overstimulated overtired children

Each summer, no matter how pressing my work schedule, I take off a day exclusively for my son, to follow his whims (as completely possible) from the moment he wakes up until he finally gives in to exhaustion. We call it dad/son day. This year our third stop was the amusement park, where he discovered (at age 9) that he was tall enough to ride one of the fastest roller coasters in the world. We blasted through face-stretching turns and loops for 90 seconds then, as we stepped off the ride, he gave a shrug, and in a distressingly calm voice, remarked that it was not as exciting as other rides he had been on.