Amazing feats have been performed due to the sugar high from consuming an ill-stashed jelly donut./s
FWIW, the harassment package is one of the few things that will preserve men in combat. Make no doubt about it. When placed in harm's way, humans behave differently to adversity. If they can't take the intentionally created high stress environment of boot camp, their reactions won't improve in combat.
I have found that I only function well in high stress jobs. The Marine Corps did that to me. I’ve had 1 job since I retired that had zero stress and I hated it with a passion. Left it as soon as I could. The job I have now is very high stress and I’m a happy camper.