It's a common exchange, heard after every winter break, at high-intensity workplaces everywhere. Someone innocently asks a coworker, "And how was your holiday?" to which the inquisitee sharply responds, "I was working." Now maybe it's just my lingering sense of guilt over the fact that I took a longer-than-normal Christmas vacation after a particularly crazy year, but this answer comes across as just plain bitchy.
It's not the fact that you worked through the holidays that bugs me; I've done that plenty of times myself. I wouldn't have a problem with the response, "Oh, it was alright. We stayed in town, and I got some lab work done. Relaxing AND productive is always a nice Christmas gift!" But no, Mr. Scrooge has to get all k3rned-like on everyone's ass instead of participating in a pleasant conversation.
For the record, it's not my fault your MIL was in town for two weeks, chasing you out of your home with her incessant nagging, and it's not my fault you had a million things to do in the lab due to your own inept ability to plan out experiments, and it's not my fault that you didn't feel you could take a break due to that two week vacation you enjoyed this past summer.*
So before you get all high-and-mighty about others' time in the lab, you best check yourself Scrooge. I'm on a mental and emotional high note right now, and I will NOT have it disrupted by your skewed sense of tit-for-tat workplace politics.
*Note added after reading some of the comments below: none of these were meant to be an attack on a specific person. Instead, I actually spent a little bit of time chatting with friends over coffee, about why people might choose to work on a holiday they normally would celebrate, before writing this. My whole-hearted apologies if any of these "reasons", or any other part of this post, offended anybody.