The other day Coworker 1 was confused about a work issue and was talking to Coworker 2 about it, who was in the cubicle next to mine. I wasn't really paying attention to their conversation and just doing my own thing in my own cubicle. After a while, I guess the coworkers found out that something I had done was responsible for the confusion, and Coworker 1 called me over. I explained what was going on. Later, Coworker 1 sorta snippily asked me, "You heard us talking about that the entire time, didn't you? And you didn't say anything then?"
I just said, "Uh... well, I was sorta in my own zone and not really listening," upon which Coworker 1 just sniffed and told me that I should be. I was annoyed at her response, but just laughed and went back to my desk.
Honestly, I think my coworker was being unreasonable because there are multiple work conversations going on all the time and I shouldn't be expected to just eavesdrop when I'm trying to concentrate on my own work. But I'm admittedly biased, because my coworker is a grumbly, waspish sort who is always complaining about something*. So I need a more objective perspective: Was my coworker unreasonable or not?
* I've lost count of the number of times I've heard her say that she hates this or that coworker. If we weren't in the same room, she'd probably be talking about how much she hates me, too. When another coworker in a different department told me that she thought Coworker 1 hated her, I told her, "Dude, she hates everyone, don't worry about it." Honestly, I probably try to tune her out more than I do other people because I'm sick and tired of listening to her complaints. I don't think telling her that would be appropriate, though.