A man was punched almost 20 times to the head in an unprovoked and random beating on grand final day in a Collingwood apartment building lift.

The 56-year-old victim, who speaks no English and lives alone in the Hoddle Street complex, said he thought Australia was a peaceful country until the attack.

"There is always a shadow," he said on Monday through an interpreter.

"I cannot sleep during the night and there are nightmares all the time."