Uncle Duke’s Beach Bar is a tiny dive hidden in the hippie neighborhood of Leucadia, Calif., just north of San Diego. Duke’s offers what most dive bars need: a good (and deep) jukebox, stiff drinks, a pool table and the type of clientele that provides entertainment for free or, at most, the cost of a PBR.

We were staying in a condo three minutes’ walk from Uncle Duke’s, and during our time there, my wife Lala and I frequented the place.

One night, Lala begged off and I made the trip alone. Things were already moving when I arrived. A gaggle of young, overdressed women huddled to the left while the main bar hosted an older and more mixed crowd.

Surfers in bare feet mingled with a few salty dogs while a man in a pressed white guayabera and matching pants chatted with a tall older woman who shimmied to an Incubus song blaring on the jukebox. I sat down at the corner of the bar next to two drunk men in the middle of an argument.

“You know what we’d do to you in southern Florida,” one said threateningly. His face was cast in shadows, but I could still make out his ruddy skin and thin eyes.

“You know what we’d do up north,” his buddy answered.

“Come on, man, you tried to hit me with your car!”

I leaned in to eavesdrop when the dancing woman plopped down on the stool to my left, literally rubbing shoulders. She had on a fitted tank top with a skull logo and a mess of African crosses and milagros hanging from silver pearl necklaces around her sinewy neck.

“What’s your story?” she asked me.

“Fresh out of stories,” I said, smelling trouble. She said her name was K, as in special, a joke she had obviously told a million times before. K never stopped moving, drumming the bar with fingers wrapped in more precious metal, and when she grew tired of percussion, she shook her bare shoulders or clapped. Her antics were hard to ignore.

“What? I’m hyper,” she said to me in mock defense.

“I thought it was coke,” the man representing southern Florida said, now alone.

On his way to the bathroom, the dandy dressed like a Mexican waiter leaned in and planted a kiss on K’s cheek. “Happy birthday, baby,” he said.

“It’s your birthday?” I asked.

“Not for two days.”

My father taught me early not to ask a woman about her age, weight or past indiscretions, but I was curious.

“I’ll be 45,” she sighed.

“So you were born in 1966, like me,” I said, ready to propose a toast to the year the Black Panthers formed or Ronald Reagan became governor of California, depending on her political leanings.

“No, I was born in ’65.”

“Then you’ll be 46.” I took a pull off my beer.

That’s when her body stopped moving and her eyeballs rolled around her head in pursuit of simple math. “Oh, man.” Her tone had darkened considerably. “This can’t be true. Not ready for 46. I was OK with 45. Hell, you don’t know nothin’.” She poked a finger in my chest. South Florida chuckled.

“It’s easy,” I explained. “2011 minus 46 is 1965.” Her face held a mix of chagrin and confusion. “Or just 11 minus 6 is 5, as in 1965.”

“No way. I gotta tell my brother.”

In my experience, when a drunk and angry woman mentions the existence of a brother, you retreat.

“Listen,” I said, “you can be any age you want.”

“If I’m turning 46, then he’s turning 51. He won’t like that at all.” She turned on her high-heeled boots and headed toward the other end of the bar.

“Suppose math wasn’t a strong suit in that family,” South Florida said, raising his glass to me.

“Guess not,” I answered, and returned his salute.