TMI stands for “Too Much Information”, when people give out far too much detail!
Some people with "TMI disorder" are way too graphic, as if we care to hear about the scent of their farts (I don't remember eating that) to the consistency of their last period (chunky).
Ewww . . . TMI
Personally, I think that TMI is a mental disorder, a form of neurosis where people become so self-centered that they think we want to hear every detail of their lives.
As a manager, I get employees with TMI disease, especially those who are going through a divorce and think that because I’m sworn to silence that they can bear their souls. Over the years I've heard some mighty weird stuff!
Here is a great source of TMI examples, TMI Incorporated: