The victim spoke with the Irish Daily Star on the condition of anonymity -- and explained why he thinks Conor socked him with a left during an incident caught on video back in April.

"I am sitting on the bar stool just having a quiet pint with my friend then all of a sudden because I refuse his drink I get a punch," the man said ... "You don’t need that in life."

TMZ Sports broke the story ... Conor had been pouring shots of his Proper 12 whiskey to people at the Marble Arch Pub in South Dublin when one man refused ... and Conor let his fist fly.

The man took the punch like a champ -- with UFC star Stipe Miocic praising the dude's "chin of steel" -- and now the guy is bragging about his toughness too.

"Look-it, I can take a punch,” he told the Irish Daily Star.

Despite the way it played out on video, the man claims the punch really hurt and he was in pain for a week ... and went after Conor during his interview.

"He is a bit of a bully, a bully with money ... I'm glad people saw the video. I don't like him."

The man still has one major beef -- but it seems to be with the media. It was reported the guy was 60-years-old ... but the man wants to set the record straight.

"I'm 50."

As we previously reported, Conor has not been arrested or charged with a crime for the attack ... and cops in Ireland say they're still investigating, which is crazy because the whole thing is ON VIDEO!!!