The Pollyanna syndrome. Is this a sort of disability?
The internet sources say that the "Pollyanna principle" (also called Pollyannaism or positive bias) describes the tendency to agree with positive ideas.
From this statement I'll focus on the "Glad game" she learnt from her father. Comming from a more mature figure, this game has other conotations. For instance, he ignores or avoids dealing with negative events, looking always for the good side and denying the bad. He made the game up when Pollyanna received a pair of crutches. In this case, he told her to be glad about the crutches because "we didn't need to use them!" Or our way of saying "it could have been worse." So it's not a reason to commit suicide for this. Stay positive. But the fact that they were poor and the awareness of it could not be washed away by optimism. Ignoring the bad by staying positive is not a real foundation of positive thinking. You must aknowledge both of them and try to remain focused on the bright side of things. As a child, Pollyanna could play "her" game more easily because she didn't have to worry about many things. She wanted to be free and to live her childhood properly. But she actually did a great thing at her aunt's house...
Self disability
A heart is like a nice pair of rollerblades. If you keep them in a box, you outgrew them. So they won't fit your feet anymore. You will grow and they will stay small and still. Therefore, if you don't use your heart, maybe it'll be like the rollerblades. When you do decide to try it, it won't be any good. This is what concernes the dispirited people in New England where Pollyanna arrives. The disabled hearts and minds are a pleasure for Pollyanna to put together using her ingenious "game". This "disability" isn't so visible, only in the attitude of Aunt Polly who is very grey and empty and who is ashamed to put some colour on her face and who is afraid to feel something.
Phisical disability
Pollyanna's accident shocked everybody. How come a pure creature like her happened to be so cruely punished? I might add here a bit of life's irony. The game isn't working anymore for she has lost her freedom, her legs which helped her run, climb, jump etc. She cries and she's completely desperate. Try to be glad now about something if you can. But Nancy, the small witted but sincere and kind maid, and all the New England "disabled" people try to teach her how to "re-glad", because "we've heard now that she's fretting her poor little life out of her, because she can't play it [the game] no more - that there's nothing to be glad about." Now the image of crutches is returning to its owner and now, not that Pollyanna will be glad that she can walk, but she will have to "wear" them insted of her legs for a while.
It's very hard to be glad in harsh moments... Pollyanna is after all a fictional character. The big picture is what people in real life do.
Happiness is also a matter of perspctive. What is good for me can be bad for you... but that's another story.