Unfortunately, the sarcasm goes right over his head. Sarcasm hadn't really been something he was privy to growing up. No, that wasn't true. Lydecker and other soldiers were good with it. It just wasn't something that Ben paid much attention to.
Why did he run? He wasn't entirely sure why he ran. He just knew that it felt good. Helped him clear his head of all the cobwebs that had been there for years. So, he merely gives her a small smile," It helps. Whenever there's too much in my head, it helps."
Running also helped curb the impulses that weren't good. Impulses that he couldn't allow himself to fall into. Not when little brother wanted him to stay out of trouble. When his baby sister had vouched for him. When he needed to help keep Dawn safe and sane.