A 12-year-old boy develops a deadly brain tumor that inadvertently floods his system with Leu-enkephalin, the neuropeptide that triggers happiness. Unwaveringly optimistic at his chance of survival, the risky surgery that saves his life also ends the euphoric bliss, leaving his brain with a cavernous hole where the pleasure centers used to be. The 18 years of sadness that follow are a downward spiral of despair, and as a last resort he agrees to another treatment that gives him conscious control over what makes him happy. As he attempts to re-enter the world beyond the hospitals and his gloomy apartment, he faces the ultimate dilemma of self-control ... how happy would you be if you could make yourself as happy as you want?

Locus Poll Award Nominee

Also included in the collection Luminous.

(From Goodreads)