Character Development is an Omnipresent Trope, it just happens whether you mean to or not. You take a character, put them through a story and regardless of the outcome, they have a new story to tell. Other times it may be a Coming of Age story, they are forever changed by the events that took place and have a wildly different outlook on life. But... they are still the same person. No matter how much you change there is something that sticks around. This trope is about the fundamental attributes of a character remaining consistent even if they (or someone else) think they've changed significantly. And they very well might have changed, but something will always be left behind. Consider a Jerk with a Heart of Jerk gradually becoming nicer to become a Jerk with a Heart of Gold, they are still a jerk. Compare It's What I Do, I Am What I Am. Contrast Characterization Marches On and That Man Is Dead.
- A season 8 episode of Scrubs had J.D. dealing with Denise, a bright but very insensitive intern who struggles to connect with patients. In a conversation about it she asked J.D. what he was going to do to fix her and he said he wasn't going to do anything, because it was her character flaw to deal with. He goes on to point out that despite having grown significantly in the past few years his girlfriend (Elliot) still struggles with her own neurosis, his teacher (Dr. Cox) is constantly getting in his own way and J.D. himself struggles with being too close to patients to be objective about what they need, complete with quick cuts to those exact problems.
- In The Big Bang Theory Leonard and Penny try hanging out together on a friend date, only for things to go sideways because Leonard realized since he and Penny weren't dating anymore he didn't have to conform to exactly what she wanted. After getting into a heated argument, Leonard later apologized and Penny commented that some part of her LIKED that he showed some backbone for a change (hinting that was one reason she broke up with him). He inadvertently backtracked to his needy self, but was a marked example of his character development.
- Justice League had a growing Myth Arc worrying about the League becoming too powerful and totalitarian, Superman specifically. When The Question discovered the history of an Alternate Universe where they did just that, he resolved that the catalyst involved Lex Luthor Jumping Off the Slippery Slope so he planned on killing Luthor himself, so that Superman can't. In explaining his plan he even says "A is A, and no matter what reality he calls home, Luthor is Luthor."
Hello, Unknown Troper. You'll need to get known to lend a hand here.