I'm a good Boy Scout. I like to be prepared for all sorts of eventualities. Whenever I go away for a trip or some camping, I tend to have 2 of everything I consider essential. 2 knives, 2 flashlights, 2 can openers, 2 dry bags, a water filter and water tablets. You get the idea. Trying to make sure that I am not without certain things. Of course, I'm also the type of person who HATES to lose things, so the chance of actually needing those spare items was minimal.
Nowadays, I am trying to use what I call the 95% rule. Do things in such a manner that 95% of the time, all goes well. It frees up some little OCD part of my brain for other things. Like my good buddy Gordon Warnica says, your brain is the best tool to carry around with you. Humans do 2 things very well. Adapt and rationalize.
Of course, Gordon uses the 80% rule. I am nowhere near that, but am really enjoying the freedom that the 95% rule brings to my life.