St. Patrick’s Day is fading into memory for another year — for those of you who can remember it at all — but this flashback was too good to pass up:

Peter Woodman, co-owner of Tommy Doyle’s Irish Pubs in Harvard Square, Kendall Square and Hyannis, says he was astonished by how St. Patrick’s Day is celebrated in the area. (Photo: Annette Montalvo)

“If you ever walked into a bar in Ireland,” Peter Woodman said, “they’d say, ‘Don’t you ever give me a green beer.’”

Things are different here.

“My first St. Patrick’s Day here, I stood out here, and my jaw was on the ground,” said Woodman, co-owner of Tommy Doyle’s Irish Pubs Cambridge locations, in Harvard and Kendall squares, and of a third in Hyannis. “What is going on?”

Woodman, of Cork, Ireland, and business partner Alan O’Sullivan, of Clonakilty, Ireland, took over ownership of the original Tommy Doyle’s in Kendall Square in 2002. Woodman moved permanently to the United States in 2006.

That is when he experienced his first St. Pat’s in the United States. “Every year I try to get my family over,” Woodman said, “because no one believes me.” Woodman said he’d seen glimpses of St. Pat’s celebrations in cities around the United States on television, but to actually experience it here in Boston was beyond what he had imagined.

On St. Pat’s, the bartenders pour 2,500 pints of Guinness and go through two cases of Jameson. And that’s just the Kendall Square location

“We opened the doors at 9 a.m. It was absolutely crazy,” Woodman said, holding his hands together, then far apart, to describe the explosion of people that came through the doors.

Trumping his astonishment at the number of people pouring in so early in the morning was the unending requests for green beer.

His beer rep told him to make sure he had plenty on hand, but Woodman thought the demand for green beer was a myth. Besides, he said, he was running an Irish pub.

“I’m not going to serve green beer, you idiot,” Woodman said he told his beer rep.

“I swear to god, you have to serve green beer,” was the reply, Woodman said. “Green beer and Guinness.”

Woodman said he bought one small bottle of green food coloring — just in case — but still thought his beer rep would be proved wrong.

It turned out Woodman was wrong. Very wrong.

An hour or two after opening, he said, he was running to the nearest store, frantically looking for green food coloring.

Four years later, he has perfected his green beer recipe and keeps at least five boxes on hand. He now uses peppermint extract. It seems like an unlikely choice, but Woodman said it works best.

“I tested a few of them this morning,” said Woodman, smiling. The man who four years earlier said he couldn’t wrap his head around the idea of green beer is now the official taste tester.

An Irishman walks into a bar …

The bar uses the lightest beer on tap, and this year it was Coors Light.

Brian Tepfenhart, 25, of Cambridge, stopped in for a lunch of corn beef and cabbage. He ordered a green beer to go along with his lunch—until he found out it was Coors Light.

“Had it been anything else,” Tepfenhart said, trailing off. He changed his order to a Guinness.

But over at the Tommy Doyle’s Harvard Square location, the Sam Adams green beer was flowing.

Evelyn Wing, a Californian visiting friends in Boston, stopped in and ordered her very first green beer.

“I never go out for St. Pat’s in San Jose,” she said. Wing said she just stopped in for one beer, but planned to come back later for more.

Paul Cassidy, 39, of Derry, Northern Ireland, also stopped in for a drink. He was in town on business and hoped to run into an old friend from Ireland. A popular Irish bar on St. Pat’s was a good place to start.

“I’m looking for an Irish guy,” Cassidy said to bartender Kate Jennings.

“So am I,” Jennings joked back.

Cassidy said he doesn’t drink beer, green or otherwise.

What about green whiskey?

“No. No way,” Cassidy said, looking startled. “I don’t want to chance it.”

But this is only Cassidy’s first St. Pat’s in America.

For a more jaundiced look at the holiday, click here.