Which is why CN is the best alignment. Pure excitement and mayhem. Climb the ladder of Chaos.
"Chaotic Neutral: Creatures follow their whims, holding their personal freedom above all else." PHB, 122.
You are leaving out the second part of CN's definition - personal freedom. They follow personal freedom. That means they follow freedom. They would be inclined to help those that are not free. They would be inclined to help the downtrodden. They achieve this through chaotic means. It doesn't mean they don't care about anything and do anything they want at any time. (Side note: I also said it was the player acting on their emotions, not ones their characters would actually have.)
Example of CN: I don't like the way this tyrant has all these indentured servants. They are not
free. So chaotic me doesn't mind wreaking havoc on his life, on his family, and on his business partners just to help free those people.
That is why chaotic and lawful are attached to good, neutral or evil.
Side note: I also said it was the player acting on their emotions, not ones their characters would actually have. You bold only part of my definition. As we know, anyone can bold half a definition and misrepresent it. As a reminder, I rewrote what I said and bolded the entire thing for you.
There are few things worse than a player that doesn't play their character consistently. But instead, they use it as a conduit to ignite whatever whim of emotion they have in RL.
See how that has almost nothing to do with roleplaying the character, but instead acting on real life whims of emotion? And it disregards the OP's implied information that they finished half of the adventure without "acting" CN.