tl;dr - was thrilling, would recommend.
There are two scary parts: the first is the waiver they make you sign. It's written as though there's a 50:50 chance of fatality or serious injury and as if the FAA actively discourages skydiving. The second scary part is jumping off the plane.
fyi skydiving looks like a safe sport. "More than 62 million jumps were evaluated, with an average of 3,200,000 jumps per year, which showed an average injury rate of 0.044% and an average fatality rate of 0.0011%." And the injury/fatality rates for tandem skydiving are likely lower.
The plane has no passenger seats and there's a side door that slides vertically up/down for people to jump out.
The plane took off and climbed to about ~13,500 ft. We past clouds on the way up.
"Elimination through substitution" has been a recurring idea for effecting change in my life. I tried to substitute fear with excitement as the plane climbed. My method for coping with uncontrollable thoughts or feelings has been trying to observe it like I'm watching a river, so I was containing the fear by watching it without letting it consume me.
And then the plane's door opened and everything in the previous paragraph went out the door, and I followed soon after. I was terrified.
Soon after I jumped out the plane, had a split second thought that closing my eyes for the entirety of a skydive is ridiculous, I paid good money for this! If/when I skydive again, I want to keep my eyes open for the moments when exiting the plane.
The fear dissipates quickly after opening your eyes and all that's left is thrill as you're falling.
After maybe 10 seconds of falling, the brain sees it as terrain view on google maps. It doesn't really register we're really high up.
After a bit of falling, they deploy the main parachute and you go from being parallel to the ground to being perpendicular to the ground (feet towards earth).
Sharp turns with the parachute deployed is thrilling, because your body is no longer perpendicular the ground (feels like 45deg but probably actually 20 or less)
For the last 50 ft on descent, I was expecting my brain to start registering "we're really high off the ground!" followed by "time to be scared!" but that didn't happen. I think my brain's height perception got disabled when getting out the plane and didn't have time to re-enable.
If space travel becomes cheap enough in my lifetime, I'll go because it seems like the brain stops perceiving height after a certain altitude. Also maybe it'll be thrilling.