At my old workplace, I recall being asked (after an extremely bad weekend), "How was your weekend?"
I didn't go into detail about the weekend's events. All I said was "Pretty terrible, actually". I wasn't ranting to anyone, or detailing things that they wouldn't want to hear.
Cue shocked faces from colleagues and the person that had asked responding with "Oh, wow, don't sugarcoat it will you?".
I was honestly very surprised. It seems that the correct answer to "How was your weekend?" should always be "Good, thanks".
I do wonder why you would ask if you weren't genuinely interested.
On a side note, I feel similar about Facebook. I share a lot of photographs of my life, and random moments that are of value to me. They're not necessarily interesting to everyone else, but I add people on Facebook because I'm interested in them and their lives. Otherwise, they wouldn't be on there. I often see comments (not aimed at me, just generic status updates) along the lines of:
"Why do people feel the need to share pictures of their pets/children? Why do people feel the need to post statuses about what they're doing?"
It's the same principle, I think. If you don't care about sharing bits of someone's life, such as enjoying photographs of their pets/children or hearing what they've been up to, why do you have them on Facebook? Surely, if you don't care, you can delete them.
I really don't understand this need to feign interest in someone else's life, when you are not actually interested at all.