It didn’t really hit me until our last day at the Magic Kingdom. My two-year-old daughter was scaling the 116 steps of the Swiss Family Treehouse for the second time. I watched her legs—once the doughy consistency of a Mickey Mouse waffle, now corded like the ropes of the treetop walkway. My daughter is strong, I thought.

I would’ve realized this sooner, but visiting four Walt Disney World Resort parks in three days—plus hopping on shuttles, speed-walking to dinner reservations, and enjoying so much pool time—hadn’t given me much space to think.

After that second tree-house run, despite my daughter’s squeals of “Do again!” we met up with my wife and five-year-old son, fresh off Big Thunder Mountain Railroad. I saw it in them, too. We were hot and sweaty and overstimulated, yes, but ready for more.