All stories must have character growth.
Growth can be subtle: the character realizes something they didn’t know before. Or profound: the character goes from ugly, wimpy nobody to strong, world-saving beauty.
Most novels go for somewhere in the middle. But whatever the case, the character in the last chapter must in some way be superior to the person we met on page one.
Basically, they must have fixed or improved upon their flaws.

Kitty Growth!
The character I had in my first draft of Aza had flaws that were very different from the character in the current version of Aza. The reason for this change was because Aza was unlikable at first. I personally thought she was pretty cool; no amount of yelling or punishment could make her feel bad–she was untouchable. She just didn’t care.
Now I realize that an important factor in making readers care is when a character is touchable. The character cares, the reader cares. The character worries, the reader worries.
My first test readers couldn’t feel sorry for Aza because she didn’t feel sorry for herself.
However, there must be a balance in the Force! Total, obliterating self-pity gets boring after a while and is best used sparingly.
In the current version of Aza, I use a self-pitying scene about four times*. In one instance, it’s a different character that breaks down. Making a supporting character feel totally helpless creates an interesting situation. It gives the protagonist a scene in which they can show their flaws, how they’ve grown, or reveal any true feelings. The reader can still sympathize, though, especially if the self-pitying character is one they’ve been led to like or respect. The other three instances are Aza’s. All her break-down moments lead to the same thoughts from Aza: ‘Nothing is going my way and I failed my tribe’.
In the first draft of Aza I had only two moments of utter despair. One of them still exists (the point when Aza is trapped in a cave), but the other one didn’t work. It was near the end of the book, right before the climax. My mom read this scene and said, “Sonora, Aza has just had over 30,000 words of life-changing experiences–why is she giving up now?”
Original Aza had issues.
*Interestingly, one of my current WIPs, Two Kinds of Darkness, only has one instance of dilapidating self-pity. Character’s main thought: ‘Why did I do that? Now I’m going to die.’