Happiness (2016)

After his mother's death, Chan Kai-yuk feels so alone that he leaves Guangzhou for Hong Kong to look up the father who abandoned him and his mom. But Yuk's hopes are dashed on finding his dad has a new family and considers him a burden. Alone and homeless, Yuk is taken in by Auntie Fen, a middle-aged recluse who leads a solitary existence. At first, their different habits and personalities lead to numerous squabbles, intensified by Yuk's self-centeredness and Fen's odd temperament. As time goes on, Yuk learns Fen is in the early stages of Alzheimer's. The discovery unexpectedly serves as a catalyst for the young man's growth as a caring friend. For the first time in her life, Fen feels truly blessed. But it is a situation rife with irony due to the nature of her disease and the accelerating elusiveness of feelings and memories.

Unfortunately the movie Happiness is not yet available on HBO Max.