Our Gemara on Amud Beis Discusses assumptions to make about the states of various items. For example if one set aside $100 of tithes, but then came back and found $200. Shall he assume this is a totally new $200 and it’s not sacred, or shall he assume that $100 is still from the tithe? And a similar question came up regarding live animals, such as if one designated three doves for slaughter and use on Yom Tov, and he came back and found only two. Can he assume that those two are from designated livestock so that it is permitted to use it on Yom Tov, or must he assume That these doves are totally different ones and the original three, though tied up together, somehow hopped away. The Gemara considers that since live animals are more active, they cannot be compared to the case of the money. Even one who assumes that the leftover $100 is tithe, May not necessarily assume that the two doves found now are from the original three.
It is the nature of living things to be in constant motion and to be unpredictable. The Chovos Halevavos (Sha’ar Habechina Chapter One) makes an interesting observation:
When one and the same thing is always being produced in the same way, it is clear that the maker is not a voluntary agent but a force acting according to the nature imposed upon it - compelling it to act in a definite way which it has no power to alter, just like fire whose sole function is to burn, or water whose nature is to cool. But one who has the power to do as his will prompts him will act in various ways at various times.
In other words, the more alive something is, the more unpredictable it is. Stones just sit as stones, it’s not a particularly hard job to be a stone. Fire and water are less predictable because they are more animated, but still they follow basic physical laws. Animals are even less predictable because they are far more animated than fire and water, however since they largely follow instinct, much of their behavior can be predicted. Ultimately, humans, who represent the highest degree of life and intellect and animation, are utterly unpredictable.
The point of this is that often we want to have our cake and eat it too. We want to live and be alive fully, and yet we loathe change and unpredictability. This is even more so regarding the people that we love. We want them to be alive and excited and interested in us, yet we secretly wish we can control them and press the off button when we find them inconvenient. But that is not what being alive really entails. In actuality, there’s no way to be alive without embracing uncertainty. Because of this continuum we described, it is simply a fact of nature that the more unpredictable something is the more alive it is.
Now of course unpredictability does not mean chaos. Chaos is random and often destructive. Unpredictability, on the other hand, is not random at all. It just is something that is responding to inner directives that we may not be able to predict or even re-create. Respecting ourselves and others and what it means to be alive means realizing that a person is capable of deciding and doing anything. That doesn’t mean that they should, it means they are alive, and we enjoy their life force knowing and allowing for that they could do anything.
Translations Courtesy of Sefaria