Does it really need to be said what this thread is?
My guess was a psychotic break.
The only time i've seen people jump into a rant with no context and without introducing themselves (unless already introduced) is with schizophrenic homeless people on the street.
Like the one time I was waiting for a bus and a lady started screaming at the snow that it wasn't going to take her boxes away. Or on the bus when the same lady (a couple months later) was ranting about buses having no room for her boxes.
Or getting pizza with a coworker, a homeless lady walked in and told us her boyfriend beat her but he was a nice guy. She also tried to sell us KFC coupons.