Dylan McWilliams doesn’t believe that old saw about lightning never striking twice.

Not after he was attacked by a shark Thursday in the waters of Kauai less than a year after he was mauled and dragged by a black bear in the wilds of Colorado. And certainly not after he was bitten by a rattlesnake in Utah a little over three years ago.

What is it about this guy that draws dangerous predators with sharp teeth?

“I don’t know,” the visitor from Grand Junction, Colo., said Friday. “I’m either really lucky or really unlucky.”

As it turns out, McWilliams, 20, spends more time outdoors than most folks. He’s a former tree trimmer, ranch hand and survival training instructor who loves extended journeys into the wilderness.

He discovered the beautiful landscape of Kauai last year when he backpacked solo around the island. He came back for another two-week backpacking tour Sunday but ended up on the north shore helping distressed residents clean up and move trees following last weekend’s torrential storms and flooding.

McWilliams observed the muddy coastal waters, and he knew that nearly all of the island was under a brown-water advisory. Huge storm events like that are notorious for turning the water brown and luring sharks for an easy meal.

By Wednesday, however, he was itching to get into the surf and decided to head south in search of clear water. He found it at Shipwreck beach in Poipu, part of the small section of the Kauai coastline not included in the brown-water advisory.

Bright and early Thursday morning the water was clear, blue and inviting with 3- to 5-foot waves, he said. There were a handful of others enjoying the surf, too.

McWilliams entered the water with his boogie board at around 7:30 a.m and caught his first wave.

As he was heading back out, another wave knocked him off his board in 15 feet of water about 30 yards from shore. That’s when he felt the searing pain in his right calf.

“At first I panicked,” he said. “I didn’t know if I lost half my leg or what.”

McWilliams said beneath him was what looked like a 6- to 8-foot tiger shark — he saw the stripes — and he gave it a swift kick before launching into a desperate swim to shore.

“That was the scariest part. I didn’t know where the shark was, and I didn’t know if he would come after me again,” he said.

On the beach his calls for help were heard by a woman who came to his aid. She called authorities, and as he sat on the beach, his leg dripping with blood, he realized his injuries could have been a lot worse.

After the paramedics arrived he turned down the expense of the ride to the hospital, and the woman volunteered to take him for help. There he got seven stitches.

In July McWilliams received nine staples in his scalp after a 280-pound black bear woke him as he slept outdoors with other staff members at a summer camp near Ward, Colo.

The bear bit into the back of his head and dragged him some 12 feet. McWilliams said he remembers waking up to the sound of the crunching of his skull, and as he was being dragged away, he instinctively fought back, throwing punches and poking the bear in the eye.

“He dropped me as soon as I did that,” he remembered. The bear stomped on him and finally slunk away as other camp staffers came to the rescue.

McWilliams told his story to ABC, CNN, People Magazine and other news outlets, including a television morning show in Great Britain.

“If I push on the back of my head, it still hurts a little bit,” McWilliams said Friday. The teeth scars are still there, but the claw marks on his forehead have faded.

It’s crazy that another large creature would try to take a bite out of him less than a year later, he said.

“I guess I was just in the wrong spot at the wrong time,” he said.

But luck was on his side — just as it was 3-1/2 years ago when a pygmy faded rattlesnake surprised him as he was hiking out of a canyon near Moab, Utah.

Turns out it was a dry bite, which gave him only enough venom to make him ill for a day or two.

“My parents are grateful I’m still alive.”