Rollover training was probably the most eye-opening and terrifying training I've done. They have this little pod that you sit in, and it rolls over and over to simulate a vehicle rollover. The inside is of course made to look like the inside of a vehicle. What you don't realize until you get in is that there is ABSOLUTELY NO ROOM in there. After all your body armor, pouches, helmet, and weapons - and the computers, steering wheel, armor, and gunner adjustments - you have enough room to sit in your seat and turn your head. That's about it. Now get flipped over a couple times, land upside down, and get out. While smoke is blowing in your face.
I found out that hanging upside down is not a pleasant sensation. In fact, I hated it. The blood rushed to my head extremely fast, and my head felt like it would pop every time I was suspended upside down.
I used to think the worst thing that could happen would be getting hit by an IED, but I think for me it's changed to being flipped in a vehicle during an attack. The thought of being helpless for those precious minutes, struggling to get free while a firefight rages on around me makes me wince.
Once again, though, I realize that I am in the right type of job. When things get crazy like that I tend to go into a zen-like trance of super calm. I think more logically. I start thinking along the lines of: what is the very next thing I need to do to get out of this situation. Then I just do it. I'm sure I'm not unique in this, but every time something crazy happens, like a burglar running straight at me with someone else's belongings, or a three car accident happening right before my eyes, or being trapped in a (simulated) smoking vehicle with four other people while upside down - I realize that I can handle the stress. The panic is there - but then quickly melts away and is replaced with a clarity I rarely have otherwise. If nothing else, I take solace in that.