Vance: I don't know what Jim's got to grumble about. My work load has doubled in the past year and I still manage. He is not doing anything different from when he arrived, as far as I can see.
Darren: Yeah, but he's not as energetic as you are. Well, no one is. But the boss doesn't blame me when I get a bit behind. He is very understanding with me. But with Jim, he goes on and on.
Vance: I haven't noticed it. But you're probably right. I wonder why he does it.
Vance doesn't understand why Jim grumbles. Darren thinks he's not as energetic as Vance is and the boss is not understanding with him. Vance wonders why.