child like wonder

Its been raining in the Atl for a few days now, and it has caused some serious cabin fever for the little man. So being the awesome dad I am I got home from the station this morning and got Stinkys, if you smelled the shit that comes out of his ass you'd call him the same thing, rain gear on and we headed out into the rain soaked yard.
Suffice it to say the boy loved it. He splashed and ran through every puddle he could find. When the thunder rolled he looked everywhere to find it. Meanwhile I am huddling under my hoody trying with no luck to keep my Chucks dry. Why wasn't I splashing in the mud with Stinky, why didn't I show him the fine art of creating the big splash? When did I grow up and lose that childlike adventurism and simplicity?
Why is it that when we grow up we lose what we had as children, and at what point is it that we lose it? During high school in the battle to fit in? Or is it later, when the stress of bills and a job take over? I don't know for sure but this morning I realized I missed my inner child.