One Sleeps Little
Appaṁ Sutta  (AN 5:137)

“Monks, these five get little sleep at night, and are mostly awake. Which five? A woman intent on a man gets little sleep at night, and is mostly awake. A man intent on a woman gets little sleep at night, and is mostly awake. A thief intent on theft gets little sleep at night, and is mostly awake. A king fettered by royal duties gets little sleep at night, and is mostly awake. A monk intent on becoming unfettered gets little sleep at night, and is mostly awake.

“These five, monks, get little sleep at night, and are mostly awake.”

See also: AN 4:37; Thag 1:84; Thag 2:37