I'm reading Quora posts for a paper. I came across this answer when reading about wastes of time: "In my opinion, when you don't prepare, you are forced to react to things happening after the fact instead of handling them in stride..."
My reaction to this is: being prepared is a tradeoff.
Say you're going out of the country.. it seems good to "prepare" by bringing your passport. That will save lots of time. And in fact, many less extreme examples also have the property of "if you prepare before hand, you'll save time later" -- BUT: you spend time preparing, and not all of the eventualities you are prepared for actually happen. And not all of the things that are bound to happen are actually that bad. If you forget to bring your toothbrush, you can get one at the hotel. If you forget to bring underwear, you can.. make do.
My thoughts here are analogous to "lazy evaluation" in computer science. The idea is that sometimes you can make an algorithm faster overall by only doing work when a request comes in, and just doing the work you need to. This has the disadvantage that it'll be slower to respond to requests, because you weren't "prepared" with the answer ahead of time, BUT, you don't waste time preparing for things that never happen.
This speaks to my physical filing system as well. My filing system is a stack. To file a paper, I put it on the stack. If I need a paper, I search through the stack until I find it. Searching takes a while; however, I rarely need anything from my stack, and I save so much time filing stuff that the total time I end up spending in the filing system is lower with the stack.
In any case, it seems like a tradeoff, and the tradeoff doesn't always favor preparation.