The Human Division (Old Man's War, #5)

by John Scalzi

“I’m a ‘the glass is half-empty and filled with poison’ kind of guy, actually,”

“I’m trying to decide what I want to be when I grow up. A nice thing to wonder about when you’re thirty.” “I don’t think it matters what age you are when you figure it out,” Brous said. “I think the important thing is to figure it out before someone else tells you what you want to be, and they get it wrong.”

the point is that the past is the past and you let things go because you can’t change them anyway.