1
general::
Also, tell me about it. I know, I agree with you, as in Since the layoffs I have been overloaded with work?? Tell me! or We had a hard time finding the place.Tell me about it! It took me all morning. Identical to a literal request to be told about something, this expression must be distinguished from it by the context and the speaker's tone. [Colloquial; second half of 1900s]
American Heritage Idioms