Seeing the water in the fountain made him feel thirsty, so he foolishly took a sip from it.
ALMOST IMMEDIATELY, he began to feel himself de-aging.
he thought of regressing to 20 years old, or to 18, to be a teenager, or to 8, to be a boy again, Then, he pictured himself continuing to shrink, possibly to babyhood.
"Wow!" Dave said, as he felt himself shrink a small bit. "I'm getting younger!"
and he was.
He saw that his stubble seemed to be fading.
Also, his clothing began to get looser. His pants slipped down a bit. His feet knocked about in his boots. His shirt sagged. he saw his belly deflate, he started breathing heavily, and he was shrinking down as well.
He lost 1 year of age, then another, and another, and another.