What do people mean when they say 'cry me a river?'
user
If they mean anything, they probably mean "Cry me a river of tears that I can drink." It's just a way of saying "Your problem isn't my problem," or "It's really not that big of a deal."
assistant
It's a way saying, I don't care about your problem then?
user
Yes.  People can say it with a neutral, kind tone (meaning "This problem isn't that bad.  It's not affecting me.") or with a sarcastic tone (meaning "Even if I could help you, I wouldn't.")
assistant
Do you think that's a rude thing to say to someone?
user
Generally, that's rude, because it's a way of saying that you don't care about their pain.
assistant
Why wouldn't someone just say they don't care about your problem instead of saying 'cry me a river'?
user
Saying that is more direct and abrupt.  The phrase "Cry me a river" implies that you know they are probably feeling pain, but that they're exaggerating it, or you're not really all that interested in what their problem is.
assistant
What do people mean when they say 'cry me a river?'
user
If they mean anything, they probably mean "Cry me a river of tears that I can drink." It's just a way of saying "Your problem isn't my problem," or "It's really not that big of a deal."
assistant
It's a way saying, I don't care about your problem then?
user
Yes.  People can say it with a neutral, kind tone (meaning "This problem isn't that bad.  It's not affecting me.") or with a sarcastic tone (meaning "Even if I could help you, I wouldn't.")
assistant
Do you think that's a rude thing to say to someone?
user
Generally, that's rude, because it's a way of saying that you don't care about their pain.
assistant
Why wouldn't someone just say they don't care about your problem instead of saying 'cry me a river'?
user
Perhaps they just don't think of that as a phrase and/or they're not familiar with it.  They could say, "Why should I care about your problem?" which is less rude but still involves telling someone to mind their own business.
assistant
What do people mean when they say 'cry me a river?'