I've realized that proactivity is just reactivity with negative latency.
What? Okay, first of all, "be proactive" is sometimes known as common management blabber, and being a one-time manager myself, I'm allowed to use it. But used correctly, "proactive" is actually a useful word. It means solving problems before they happen.
And reactivity is solving problems after they happen. Aha. So proactivity is just reactivity where the effect happens before the cause: negative latency.
Easy, right? Well, no, since because some something or other with the space-time continuum you can't actually do that. But negative latency has been successfully employed in the past.
Here's what I'm thinking. If you operate in a normal "reactive" mode, your simple goal is to react as quickly and accurately as possible. Having given up on preventing problems, you want them to at least go away, if at all possible, before too many people notice. This is a good way to run a startup company, where you can't possibly expect to prevent all problems at first; there are just too many of them to start with.
The better you get at being reactive, the faster you can solve the problem, and latency approaches zero.
Imagine if your boat hits an iceberg and gets a hole in it. You want to start bailing water as soon as possible. If you notice that the hole is too big for that to work, you'll need to start evacuating the ship, and so on. But the better you react, the fewer people who drown.
As latency approaches zero, the amount of work increases exponentially; latency can never really reach zero using a reactive method, but it can come infinitely close with an infinite amount of work. This is a singularity.
Now what about that negative latency? Well, it requires some different techniques, and creative thinking, versus positive latency. Since you can't run time backwards, you have to instead be living in the future, reacting now to what you expect to happen, say, 10 minutes from now. Living in the future is impossible, of course, but you can try your best to predict what it will be like. And predictions are about probability. This is the only real difference between being reactive and being proactive.
Many people don't realize this, and think of the two concepts as requiring a total change in technique: "proactively prevent all problems." This leads people to overanalyze the situation, taking only extremely safe, risk-free approaches that will never have problems - but will also be the slowest possible way to get there. This is sort of like sending all the bytes from all the files just in case the TFTP client might want them someday.
In fact, just like the current problems that you react to, each future problem has a cost associated with its occurrence, and increasing costs associated with not solving the problem once it occurs. Reactivity helps you avoid that increasing cost; proactivity removes the fixed initial cost. But while reactivity has an easy-to-calculate cost-to-benefit ratio (you know the cost of not solving the problem, you know the problem has occurred, and you know how much it'll cost you to solve it), proactivity has an extra element to it: risk. Some potential problems, even though they might occur, won't. For those ones, avoiding them is purely a cost and has no benefit.
So as with all negative latency problems, probability and intelligence are key. But you can outdo anybody who is merely reactive or naively proactive, just by thinking harder and more carefully than they do.