Life is actually more like an extremely complex and constantly changing equation, full of variables: the times, environment, family, opportunities, health, cognition, personality, choices, and even luck. And these variables are not simply added together, but rather influence and constrain each other.

Many people like to understand life as a linear "input-output" relationship, as if as long as you put something in, you will definitely get the corresponding result.

For example, some people believe, "As long as you work hard enough, you will definitely succeed." But they often overlook the fact that success never exists in isolation from the environment. The same effort can yield vastly different results in different eras, on different platforms, and with different resources: some people ride the wave of opportunity and rise to prominence, while others waste their lives struggling against headwinds. Effort is certainly important, but it is only one variable, not a universal formula that determines everything.

For example, some people believe that "working hard to make money when you're young will ensure happiness in your old age." However, the problem is that no one can be certain they will smoothly reach that "old age." In fact, many times, it's precisely because of long-term overworking, sacrificing health, and mentally exhausting oneself in youth that the body collapses prematurely. Thus, before one even has a chance to enjoy the future, they have already lost the ability to face it.

Often, reality is not a stable assembly line; it's more like a dynamic system—variables are constantly changing, conditions can be reset at any time, and formulas that held true in the past may not hold true in the future. Many seemingly self-evident life logics are essentially just phased experiences under specific circumstances, rather than universally applicable truths.

Therefore, what people truly need is perhaps not to cling to a fixed formula for life, but to always maintain a sense of awe for "variables." Knowing that life cannot be absolutely controlled, and understanding that many things cannot be achieved simply by "trying" or "planning."

This realization is not pessimistic; on the contrary, it means that a person begins to truly understand the complexity of reality, and therefore understands better how to maintain balance, exercise restraint, and cherish the present moment.

And only then can one truly understand the meaning of the phrase "life is unpredictable".