THERE'S something about the internal fear system that can really play with your mind. The surge of adrenalin, the little voice inside screaming "abort, abort" and the need to jump out and run away are all part of it.
But sometimes you need to just harden up and put your head down. When the initial fear reaction is the result of just how far down your head is, there's a whole new set of issues.
We took to the desert just outside Los Angeles in Jeep's brand-spanking Cherokee. Putting it through its paces on a tough canyon crawl triggered one of these palpitation-producing moments.
It was the point when I felt the seatbelt take my weight that the reality of just how steep a grade we were descending really sunk in. I'm ashamed to say that my taste for a cold beer after work and a hot pie during, lends my body to be less athletic that it could be. Fortunately, they're good strong belts in the Cherokee.
As the nose drops almost out of sight, the rock formations on either side start closing in and the subconscious starts having conniptions there's a point when the brain's safety mechanisms need to be turned off. Not easy, but it all comes down to trust in the vehicle you're driving.
So with this in the back of the mind, setting off to the States on Monday my hopes weren't exactly high. After seeing photos of the new Cherokee - which polarised the Jeep fan community of 2000-plus worldwide websites - and noting the huge gap between the Alfa sprout and the Cherokee's core abilities, it could have gone either way.
Fortunately, Team Willys, it went well. Incredibly well, in fact. The quality of the Cherokee has lifted massively over the last one, it's more than capable on the dirt and has gained some real on-road performance.
Needless to say, that few seconds of weightlessness seemed like forever, but as the Jeep's hill descent control cooled my need to get back on the level it became abundantly clear that this vehicle has changed where the Cherokee is pitched.
Jeep's designers were given something as close to free reign as large studios get - after weeks of banging their collective heads against a wall trying to get a bit of funk into that same boxy form, they were let off the leash. While giving designers a head to do what they want can be an incredibly dangerous thing, it gave the Cherokee a more modern feel, and while the purists might scoff at its radical departure from forms of yore, it is more likely to light the sales charts up with its current lines than the old squared-off approach.
The Cherokee has been split into two distinct ranges - the ballsy Trailhawk, focussed as the name indicates more on the dirt than the boulevard, and the Limited, which forgoes some offroad tricks for a bit more refinement.
Neither are really going to beguile the legions of dyed in the wool Jeep fans, but we'll let you in on a little secret - if it wasn't for this type of crossover vehicle out of the Jeep gene pool, there wouldn't be a Wrangler.
To keep building something as shamelessly un-PC that scoffs at potholes and the odd cliff climb and, let's face it, always looks cool at the beach, Chrysler needs the Jeep nameplate on something that could cross not only the fine line between road and rough, but could cross the brand's traditional buyer line and pick up some newbies. The two new Cherokees make this far more of a reality than anything else we've seen to date.
While Australian final spec and pricing are still not confirmed, what we do know is that both iterations will hit our market. We will be taking the three engine options: a 3.2-litre version of the Pentastar V6, with altered bore dropping the capacity while retaining a solid delivery of 324Nm of torque and making 202kW; a 137kW/231Nm 2.4-litre MultiAir2 TigerShark I-4; and a two-litre EcoDiesel that wasn't available to test on this press launch, but is likely to be a big model for Fiat Chrysler Australia when we see the cars in the second quarter of next year.
The nine-cog wonder only really becomes hard work if you're relying on manual-style shifting through series of very tight turns, or when you're climbing extremely steep grades. It also means highway performance gives excellent fuel economy and a far lighter carbon footprint than normal.
The bulk of our driving was on tight and twisty canyon roads between California's Westlake Village and Malibu, a money belt packed with houses the size of hotels with gazebos that would eclipse the average Kiwi residence.
The famous Mullholland Drive, which winds its way around the eastern ridge of the Santa Monica mountains, and features the aptly named Dead Man's Curve, was a good facsimile of the type of roads that dot the Aussie landscape.
Tight bends that just keep turning in on themselves, quick drop-offs and steep climbs make for a challenging environment for any SUV, and most soft-roaders. But it did underline Chrysler's confidence in the new Jeep, which is aimed more at the Toyota RAV4 and its ilk than the hairy-chested mud monsters that the Wrangler and the Grand Cherokee foot it with.
The surprising thing was just how tractable the 3.2 Trailhawk 4X4 we tackled this drive section in actually was. It exhibits the sort of turn-in that its predecessor was simply incapable of, and can swiftly change direction with a dab of brake, swing of steering wheel and a good dose of accelerator. Even on the off-road tyres that were fitted to the Trailhawk, it was a very usable SUV, up to the standard of most of its declared competition, and in some cases far exceeding it.
The Limited - driven with the 2.4 MultiAir2 - was even better, due in part to the tamer tyres that it was shod with, but more to do with more of a road-tuned chassis than its dirt-loving sibling. It rides like a lofty mid-sized car, whereas the earlier Cherokee rode like a large car from the early 1970s on bad tyres.
But it's when the road gives way to dust, rocks and mud that the Limited lives up to its name. It's capable of dipping its toes into the dirt, but the Trailhawk is much more at home. It proves that off-road ability comes from more than four letters on the bonnet. Jeep Compass backs this up quite ably.
This is also used in straight canyon crawling to great effect, with the Speed Select allowing the same adjustments when tackling threatening terrain. The pedals remain untouched during both of these processes - but a lingering brake foot is always a wise back-up. An easy toggle switch snips quickly between auto, snow, sport, sand and mud, or the touch rock setting for the best diff and 4WD setup to tackle almost anything.
Other electronic offerings adorn the well-designed interior, which has given away the same boring and boxy style as the outside, with swooping curves and exceptional use of contrasting materials. Hard plastic materials have been binned in favour of softer-touch choices, and sneaky storage options allow easy stowage of a lot of the junk that we seem to cart around with us day-to-day.
The dash is very well conceived: USB, aux and even an SD card slot at the base of the centre stack, complete with a cellphone storage pocket to avoid tangled cables around the cockpit, and a big 8.4-inch screen sits front and centre with Chrysler's well-sorted one-touch UConnect system allowing easy access to media, radio and navigation settings as well as stored phone books and other vital ingredients of modern life.
Safety features are as expected - collision avoidance, lane keep assistance with automated steering, 10 airbags, adaptive cruise control and even parallel and perpendicular automatic parking for the incapable, the lazy or those who don't want to scrape their rims on high kerbs.
Chrysler has not only broken out of the box with the Cherokee's wildly revised shape, squinting frontal light treatment and lower waistline, but it's picked up the road manners that have long been missing. Add the fact that it's got some genuine off-road abilities that turn it into a crossover by nature, not just name.
When it arrives Down Under - with a 2WD option for those who accept the fact that the bulk of their driving will be on sealed public road - it really could put a whole new spin on just what vehicles in this rapidly growing and hard-fought sector should be able to do.