NSW man too drunk to remember attack

When police came to Christopher Speight's home and told him he had punched a man at a Sydney nightclub months earlier, he thought they had the wrong guy.

"I didn't believe I had done anything wrong ... I thought it was a case of mistaken identity," the 29-year-old says.

But upon being shown CCTV footage of the attack, Speight couldn't argue with them, despite having no memory of the event.

Sydney's District Court heard on Wednesday the chef had consumed so many beers and shots he didn't even remember how he got to Candy's Apartment in Kings Cross in the early hours of the morning one night last November.

While on the dance floor of the Sydney club, CCTV footage shows Speight running towards "completely unsuspecting" 24-year-old university student Sebastian Bell and punching him in the head.

He suffered serious fractures to his jaw.

Speight, who has pleaded guilty to recklessly causing grievous bodily harm told his sentence hearing his New Year's resolution was to stop drinking.

"My health had started to deteriorate ... My wife doesn't drink and I don't think she likes a drunk husband."

The court heard Speight had been drinking heavily since he was 14.

"When I was 21 and 22 years of age I used to drink round the clock just to function," he added.

Judge John North said character references of Speight described him as a kind, hard working man.

This was hard to reconcile this with the person that appears on the CCTV, attacking Mr Bell, he said.

Speight will be sentenced later this month.