WARNING: Tempting terminal gravity may be hazardous to your health. Swooping around in the wind tied to an artificial wing is not the safest summertime activity. Taking a Cessna from altitude to the tarmac is not for everyone. But these activities can be damn fun.

The realization comes not too long after gravity sucks me and the man strapped to my back out the glowing doorway.

It emerges after a minute and a half of freefalling over a vast patchwork of valley greens and barely believably oceanic blue.

It arrives after 18,000 feet of plummeting has me laughing deeply, almost uncontrollably – and after 120 mph’s worth of wind resistance has me crying in a cloud.

It hits me after my feet hit the ground and, unclipped from Skydive Monterey Bay’s Daniel Crews, report a weird wooziness tingling around my toes. I feel it in my hands, my legs. It leads to the realization that makes me smile: I was wrong.

“I wish I could make it more complicated, but I can’t,” Crews says, concluding a brief, simple and straightforward orientation before loading us into a King Jet once owned by the governor of Missouri. “The scariest part is when you pay.”

Actually, Crews is wrong. Fortunately, this is an isolated incident.

The scariest part is completing the waiver: initialing no fewer than 19 different versions of risk indemnification, risk assumption and risk contemplation, copying down a very specific and not-so-sunny sort of phrase (“I realize that skydiving, parachuting and flying are inherently dangerous activities that can result in serious injury or even death”), then signing another eight blanks absolving Eclipse tandem strap systems of any possible beef.

From there, it’s sweet, albeit tempered, anticipation – I have already prepared myself for fog-driven disappointment after the kind dive-shop manager, Dail Greninger, told me my leap was pending clear skies because of some silly Federal Aviation Administration rule about keeping skydivers out of clouds planes could potentially fly through. (Crews adds that Europe has no such statute.) It’s been unseasonably overcast all week, which means I could be there until 3pm without leaving the ground, something that happens regularly in June and July – aspiring fly girls and boys would do well to check the weather reports.

But the skies crack open like a warm heavenly cookie, dripping Marina with sunshine and our group with smiles. There will be fun.

Two skydive photographers with lenses strapped to their helmets appear wearing sleek jumpsuits with cool colors and armpit wings. I feel under-equipped, and say as much. Jackie Care quickly disappears and then materializes with a money red onesy. No wings, but no worries – this thing is sweet.

THE 90-SECOND FREEFALL FELT LIKE FIVE SECONDS. AND SUPERHUMAN. AND UNLIKE ANYTHING ELSE.

HAlf of the day’s divers launch first. I watch them lift off with the father of one of the jumpers. “This was always my dream,” he says through an accent, touching the back of my neck. “But I have bad back here, and my knee is not my own. Now my boy will do it.”

We taxi over to see them tumble from the sky. They are different people when they land. One twentysomething wears a look like he just consummated some sort of situation with Jessica Simpson.

I try not to get too eager – I want the chance to fall far and fast to come as quickly as possible, and over anticipation will just make it arrive more slowly.

As it turns out, the next events go way too quickly: We climb to 4,000 feet higher than Mount Shasta in 10 steep minutes. By the fifth episode of ear popping (read: gum is good), Crews has me strapped to him and inching toward the door. His earlier words echo in my replugged inner ear. “We’re gonna be close,” he said. “Inseparable, really.”

I don’t feel nervous. Photographic evidence later suggests otherwise – I’ve never seen such a bizarre grin on my face before.

“Do you feel that?! What is that?!”

I’m shouting in a patch of sun-scorched grass near the Marina Airport. Crews looks at me like he knows the feeling.

Minutes ago he stood behind me at the edge of the Peninsula’s roof, some three-miles-and-then-some up in the sky. I stared, happy in the blistering wind, reveling in the view, anticipating the imminent “One...two… three.” It never came.

Instead, Crews dipped us out suddenly, deftly turning us into the wind shooting past the plane to stabilize us – while arching us in a big graceful gainer. In seconds we were thousands of feet from the iron bird that birthed us, hurtling toward earth, my hands on my straps, Crews guiding us through the opal sky.

The command to open up my arms to help control our fall came with a tap on the shoulder.

The involuntary shouting had already shown up, starring a host of exuberant expletives. The dryness of my mouth resulted from having it open the whole time. Around us, Laura Mullen and Care buzzed about like hummingbirds, using breath-triggers to snap photos of the goofiest-looking creature in the atmosphere.

The 90-second freefall felt like five seconds. And superhuman. And unlike anything else. In short, it felt great – in a classic, words-can-never-do it-justice kind of way.

Then, as suddenly as it started, the freefall swooped away, our parachute yanking us into a pleasant floating reverie above Marina. As the Peninsula breathed beneath us in vivid color, Crews twirled us in circles by controlling our sail – but I was already dizzy with excitement. Our shadow centered on a circular rainbow on the clouds beneath us; not even a world-class ping-pong player could’ve smacked the smile from my face.

I lifted my feet and Crews landed us smoothly. Soon I was shouting my questions about the buzz I felt kidnapping my person.

He shook his head with a hint of “young grasshopper.”

“There are a lotta things out there,” Crews said. “But nothing beats skydiving.

“That feeling? That’s adenaline.”

That’s when the realization lands: After recent stunt plane escapades, a white-water-rafting wipeout and a cliff-jumping jaunt, I thought I knew what adrenaline was. I was wrong.

SKYDIVE MONTEREY BAY, INC. | 721 Neeson Rd., Suite 1, Bldg. 533, Marina 1-888-BAY-JUMP www.skydivemontereybay.com | $199/15,000-foot jump; $259/18,000-foot jump.