system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Why wasn't Luke at all affected by killing everyone on the Death Star?

Was it a legitimate military target? Yes. Was it nesecarry? Yes. Did it arguably make the world a better place? Yes.

At the same time though; he killed probably over a million people and even if it was morally justified that's not the kinda thing you can do without some form of guilt or ptsd; especially if the force would have made him cognitively aware of at least some of those deaths.
gpt
There was probably a lot of introspection and self-doubt between ANH and ESB. Right after the Death Star's destruction, though, he's just happy to have survived. By the time ESB rolls around he's probably processed it as something he had to do.

It's the same reason we don't see Leia's grief at losing her homeworld. Once the post-battle euphoria wore off, she was probably inconsolable for a long time. But ESB takes place three-and-a-bit years later, which is plenty of time to work through grief.