Let's not forget about the horrifying truth that Luke's aunt and uncle were burned alive in search of C3PO and R2D2. Luke came home to that. That's traumatizing. He had zero time to process that. A few days later he was in an X-wing trying to take down the Death Star. Life is funny that way. One day you're moisture farming with your aunt and uncle, the next minute you're killing thousands of people in a terrorist attack.
Have you heard that argument? The argument is that when Luke destroys the Death Star it's very similar to a terrorist attack. There were thousands of people on board, many of them being non-military personnel. That turns the whole story on its head, doesn't it? You could argue that even if that's true it was for the greater good, but still. What about all the janitors?