During a stay in Copenhagen while touring, Green Day accepted an invitation to sleep at a fan’s home, only to be introduced to the host’s “roommate”: a human head preserved in a tank of formaldehyde. The unsettling incident later helped inspire the title of the band’s 1995 song ‘Brain Stew’, turning an unlikely tour anecdote into part of their creative history.

Billie Joe Armstrong recalled that the head, apparently obtained from a medical school, was bald and still had pins in it. Armstrong chose to sleep in the hallway, while Mike Dirnt said he slept beside the tank and joked about greeting it the following morning; the story resurfaced in a retrospective interview.