Yossi Ghinsberg oozes a palpable joie de vivre, and he should. The last 20 years have been a gift. He ought to be dead, and he knows it.

When Ghinsberg got out of the Israel Defense Forces, he hit the ground running. He made a ton of money working in the canneries of Alaska and blew it all in Vegas. He loaded trucks in New York City and, finally, made it to South America.

It was in Bolivia that Karl, a mysterious older man, talked Ghinsberg into making the journey that forever altered his life.

“He told me he was an Austrian geologist leading this exploration and making contact with a tribe that had never seen civilization before and there was gold. This was classic: Indians, gold and uncharted! I was begging him to take me with him,” recalled Ghinsberg, in San Francisco this week on a national book tour for his memoir, “Jungle.” His story also is told in a Discovery Channel series next month.

“In retrospect, he made up this story for me. He was no geologist and there were no Indians or gold.”

So, along with friends Marcus and Kevin, and his dubious guide, Ghinsberg set off into the unknown. Local Indians warned the rainy season was upon them and it was the wrong time to start a journey, but Karl assured them he knew what he was doing.

And he did. The Austrian was an amazing outdoorsman, but it soon became apparent that he was also not of sound mind. Ghinsberg thinks Karl actually believed his own stories of Indians and gold, but they were a fairy tale. Meanwhile, the four of them were weeks into the jungle, caught in incessant rains, and Karl had, inexplicably, left about 90 percent of the supplies and provisions behind.

With the veneer of society rudely shoved aside, the group’s cohesion broke down. There was a split: Ghinsberg and Kevin decided to raft to civilization, Karl and Marcus would hike overland. The latter two were never seen again.

Ghinsberg and Kevin were soon parted when their raft struck a large rock and toppled over a waterfall.

Ghinsberg washed ashore with no lighter, no machete and no gun. It was here his true nightmare began.

In the next three weeks, the Israeli would pray to

die. Skin diseases reduced his body to an open sore. Sans a machete, he was forced to claw through the jungle with his bare hands, and was bitten by every manner of insect. Many laid their eggs in his flesh, and the larvae squirmed when he scratched his wounds.

The rain never ceased, and, at one point, a storm struck with such ferocity that huge trees crashed around Ghinsberg’s improvised shelter. The ensuing flood carried him away before he even had time to put on his boots. By the time a rescue boat showed up, Ghinsberg hardly believed it, because he was already hallucinating the sight and sound of helicopters and boats nearly constantly.

His Judaism gave him strength throughout. When he miraculously pulled himself from thick, swampy mud or fended off jaguars, the deadliest snakes in the world or a 6-yard-wide swath of carnivorous termites, he saw it as an intervention. And he still does.

And in his pocket the entire time was the tattered portion of the Zohar, given to him as a talisman of good luck by his Uncle Nissim, a rabbi. Nissim claimed the Hebrew inscriptions had saved his own life many times, and, not two hours after he handed them to his youngest nephew, he died of a heart attack.

“If anyone tries to invent this story, they can’t,” said Ghinsberg, shaking his head. “So many things happened to me that are unbelievable.”

“Jungle” by Yossi Ghinsberg (Boomerang New Media, 241 pages, $23.95).
“I Shouldn’t Be Alive” airs on the Discovery Channel at 9 p.m. Friday, Nov. 11.