A gap in knowledge

From the Christian Science Monitor review of the book Made to Stick:

The Heaths discuss, for instance, what they call "the gap theory" of curiosity. This is the notion that a gap in knowledge is painful – it's like having an itch that needs to be scratched.

That reminds me of:

Guyal of Sfere had been born one apart from his fellows and early proved a source of vexation for his sire. Normal in outward configuration, there existed within his mind a void which ached for nourishment. It was as if a spell had been cast upon his birth, a harassment visited on the child in a spirit of sardonic mockery, so that every occurrence, no matter how trifling, became a source of wonder and amazement. Even as young as four seasons he was expounding such inquiries as:

"Why do squares have more sides than triangles?"

"How will we see when the sun goes dark?"

"Do flowers grow under the ocean?"

"Do stars hiss and sizzle when rain comes by night?"

(Jack Vance: The Dying Earth)