OP
Exactly.. We spend a lot of time making sure you have your "Mora" knife when you are out in the forest, but you would be much better advised to leave the knife home and make sure you had a good filter in your pack... There are some very nice filters, with a pump function that can produce five gallons of good drinkable water in a relatively short time.
The other side of the "coin", I have with absolute impunity consumed ground water from a lot of places. I have in a pinch drank water out of tundra ponds that looked like "Earl Gray hot"... That is a bit like playing roulette, a good friend of mine a member of my "cohort" in Alaska, Ran out of purified water, and drank some out of a tundra pond, and within 18 hours, was praying for death, because he was so sick.
The single most important substance for life as we know it, here or anyplace in our universe, is liquid water.
More important than making fire, or any of the "imagined survival skills" is the ability to find water. We can live for a long time with out a lot of things, the exception is water....
We existed for probably 2 million +/- years, before we found fire, but we would not have made that journey without water...