A Different Differentiation

Math textbooks always point out the prevalence of algebra and calculus in other areas of study, such as physics, economics, and science. These references deal with specific equations - the velocity of free falling object, given by s(t) = h - 16t^2, is a standard example. Recently, I've found that calculus can influence my way of thinking, as well.
Life is complicated. We interact every day with hundreds of friends, acquaintances, and strangers, and on top of it we keep track of other people's relationships with everyone else. We need to form priorities from an infinite amount of tasks that range from present concerns to future plans to past shortcomings. At our busier moments, the whole thing can seem like a mess, a giant implicit differentiation problem with a nasty mix of trigonometry and fractional exponents. How to make sense of it?
By differentiation! Look at any given situation as a very squiggly graph. We want to understand the cause behind the changes occuring, and the only way to do that is to find its derivative. Once we get to the bottom of it, we are capable of steadier decisions and behavior, even when caught between two squabbling friends. The same view applies to historical events, and really anything that involves interaction between people. I suppose we could even seek the second derivative and beyond... to the equation y=c, where slope remains constant and all things are timeless. Of course, look where that got Thomas Beckett in Murder in the Cathedral...