Everything Maurice Sendak touched had an immutable aura of wonderfulness to it, from his beloved children’s books to his little-known posters on the joy of reading to his energy as an educator. Among his earliest and loveliest gems is Let’s Be Enemies (public library), written by Janice May Udry and published in 1961 — the same year that young Sendak received that remarkable letter of encouragement from his editor and patron saint, the great Ursula Nordstrom, and also the year that he created his magnificent Tolstoy illustrations.

This endearing reverse-psychology story about the silliness of quarreling as a lose-lose proposition is in some ways the mirror image of Ruth Krauss’s I’ll Be You and You Be Me, which Sendak illustrated seven years earlier. Here, 33-year-old Sendak exercises his faux-curmudgeonly side through the tale of two little boys who decide to be enemies, only to realize how much richer life is when they’re friends — a charming reminder for all of us that self-righteous indignation is never an appropriate, or a soul-satisfying, response.

Complement Let’s Be Enemies with the immeasurably wonderful I’ll Be You and You Be Me and Open House for Butterflies.