For the book this archetype is named for, see Pollyanna.
Blithe Spirit Wide Eyed Idealist characters who undergo various hardships, losing almost everything they hold dear, and yet seem never to lose their sunny disposition. Think Happy Thoughts may be how these characters do this.
When these characters are played for drama (which usually entails a Break the Cutie situation), you sometimes get the feeling they're conducting some serious repression in order to continue functioning, and we are likely to see them break down; on the other hand, their infinite patience and good humor may give them away as All Loving Heroes. It certainly is a subconscious choice to view everything optimistically, but a lack of any understanding of the real bleakness helps and averts the aforementioned serious repression though not necessarily the insanity part. If they're members of a group that The Hero appeals to for help, count on them being the Least Is First.
When they're played for laughs, the fates the characters endure are too horrendous to actually happen in real life, and yet they're too stupid, or insane, or both, to realize how God-awful their situation is and how miserable they ought to be; it seems as though the whole universe is out to Break the Cutie, and failing. (Although sometimes they just need a Rage-Breaking Point.)
The Trope Namer is the title character of Eleanor Porter's 1913 novel Pollyanna, who was made famous in the 1960 Walt Disney movie, and was mocked by Alan Moore in the aforementioned throwaway joke in the pages of The League of Extraordinary Gentlemen. However, it was popularized over a century earlier by Dr. Pangloss from the novel (and later Broadway musical) Candide, who is always explaining why getting kidnapped by pirates or sold into slavery is ultimately for the best. Indeed, the adjective Panglossian has been in use since the 1800s.
May be an unstoppable force of goodness and optimism if (if female) she's a Princess Classic. Both are likely to cheerfully say Silly Rabbit, Cynicism Is for Losers! In a Four-Temperament Ensemble, this character is usually Sanguine.
Compare Genki Girl, who is excessively energetic, and Plucky Girl, an action-oriented variant of The Pollyanna.
Contrast Stepford Smiler where this trope is just a facade and Jade-Colored Glasses, its polar counterpart. Knight in Sour Armor for someone with a similar attitude but a lot more snark and pessimism. Polar opposite of The Eeyore and Broken Bird.
May overlap with Angst? What Angst?.
