Though he understood children deeply, Mr. Sendak by no means valorized them unconditionally. “Dear Mr. Sun Deck …” he could drone with affected boredom, imitating the semiliterate forced-march school letter-writing projects of which he was the frequent, if dubious, beneficiary.

But he cherished the letters that individual children sent him unbidden, which burst with the sparks that his work had ignited.

“Dear Mr. Sendak,” read one, from an 8-year-old boy. “How much does it cost to get to where the wild things are? If it is not expensive, my sister and I would like to spend the summer there.”

Look at the world around you. You are already where the wild things are.

Sendak’s imagination will be missed.