Think back to the original STAR TREK. Captain Kirk fell in love and lost the girl to some horrific fate, and he was sad, but in the next week’s episode, he was the same Jim Kirk as he was at the beginning of the last episode. He lost battles and friends, but the next week, he was the same Jim Kirk. He remained the same Jim Kirk throughout the whole series. He was a Teflon hero. Life experience slid right off him, and he remained the same.
But that was okay because all TV heroes were much the same back then. Each had a Teflon coating so experience wouldn’t change him. TV series were episodic rather linear, and each episode was an emotional reset to the original characters.
Today, the series characters do change on TV with the more linear story-telling, but, even then, they don’t change that much. Think of Neil Caffrey in WHITE COLLAR. He has wobbled back and forth emotionally on whether he is a criminal or a good guy through the series, but that’s it. Mostly, he remains the same person.
In genre fiction single titles like romance, characters do change as events affect them, and they tend to stay changed through the book. In a series, however, the changes in the character tend to reflect the type of story being told.
Urban fantasy usually has a main character who changes as the series progresses. Harry Dresden and Maxine Kiss have grown emotionally. One series that I’ve admired for the changes in the main character is Darynda Jones’ “Grim Reaper” series. Charley has even dealt with PTSD after she was almost tortured to death, and it took over a book for her to deal with it and come out on the other side changed.
Action/adventure of the Clive Cussler variety continues the tradition of the manly man Teflon hero.
In your own books, you must decide if your main characters are Teflon or not. Part of that decision is based on genre and audience expectations. What do readers of the types of book you are writing expect? The other part is author decision. What kind of character do you want to write?
But consider the problem with Teflon and the reader. The reader is much less likely to stick around without character change and growth.