While visiting the Atlanta area, I walked through a lovely park with a wide path where people could jog, run their dogs or ride trail bikes. As I descended a hill, I saw a woman coming toward me, pushing a stroller with two toddlers in it.

"We're coming to a hill," the woman announced to her children, "so you'll have to help me. Are you ready?"

I wondered how the little ones could be of assistance, but as I passed by I heard them earnestly repeating their encouragement:

"I think I can, I think I can..."