Somehow, though he wasn't quite sure exactly how, Luke understood Siri was trying to explain herself and the mindset her and the other Jedi had had in her time in regards to Anakin. Though it was difficult for him to understand how no one could have known or caught on to anything. Had Palpatine's influence been that good that the changes were so subtle and far between that no one knew what was happening until too late? Perhaps, for Palpatine was capable of a great many things, most of which weren't good. "I understand. If Palpatine really was involved, then his influence could have gone unnoticed." Though Luke would still like to believe that Obi-Wan or Yoda or someone would have noticed. But for the Jedi to have been Purged as they had been, it had to have meant no one knew in enough time to protect themselves or to stop it.
Luke returned the smile, glad that Siri was trying to calm down and move on. He knew this was hard for her to talk about, he could feel it in her Force Presence. The last thing he wanted to do was upset her, so he allowed them to move on to a different topic. Hopefully the shift would help her clam down again.
When she wanted to know about Obi-Wan, Luke couldn't help but feel a little sad. He had seen his Master die at the hands of Vader. But he quickly pushed that particular memory from his mind. He thought back to his time with Obi-Wan and he couldn't help but smile warmly. "Ben was okay, yes. He was, of course, careful at staying out of the Empire's sight, but he seemed to be all right. He was my first Master to start training me in the Force. The Empire had found my aunt and uncle and killed them, so he took me off of Tatooine." He thought hard for some moments, recalling that time that had only happened three years before he'd arrived here. "He had a good heart. I just wish I could've known him longer. My aunt and uncle didn't like him hanging around me, so he'd kept his distance until the Empire made trouble." He hoped that Siri would find comfort in his words, that Obi-Wan had survived and had started doing everything he could to resist the Empire. Even though Obi-Wan had died before his training was complete, the Jedi Master had set Luke on his path to his destiny. While Luke himself didn't know exactly what that destiny was, judging from the Jedi from his future that were here, he helped restore the Jedi Order.