>>893117This is one of those memes that doesn't stand up to much realistic thought. Yes, if you are getting shot at you'll go full adrenaline beast mode but you're still limited by your level of fitness. Scared shitless or not having more weight will mean you'll be slower, and if you have to drop your pack (because you can't just drop the water without rooting through everything).
I agree you have to take water, but it makes more sense to take 3 or so liters and make finding water your number 1 priority.