I've been fired twice, from shitty jobs by shitty companies where I had shitty managers.

Both times I had seen the writing on the wall and had already moved all personal items from my space. "Oh - you need to see me in HR? OK"

"You might want to grab your personal stuff"

"Nah - I'm good"

Both times I simply stood up from desk, mid-project, without even saving those last docs or shutting off my computer.

I think usually we know we are in a relationship that's not working and we're just not sure who is going to break up with who first.