(1) We begin with the simplest of questions: what are the "problems" of physical reality, low-level organisms, conscious animals excluding man, and then man himself?
(2) Physical reality has no "problems" whatsoever, neither problems created by itself nor those created by any other thing. Continuing to exist in its errorless state- without any awareness of a past or future- physical reality simply and automatically accomplishes what it's destined to do. There are no "tragedies" in physical reality; even the ripping apart of a star into a black hole is simply the unremarkable distribution of matter from one location of physical reality to another. Not a tragedy; not even a problem.
It's misleading to speak of physical reality "obeying" physical laws and equations, as if this was a burden or duty that physical reality must fulfill or comply; physical reality doesn't check the equations and laws first, perform calculations, and then do what these equations and laws "require." Physical reality's mere existence is always perfectly in tune with the physical laws and equations; it never "exits" this in-tuneness whatsoever.
(2) The problems of low-level organisms (uni-cellular bacteria, plants, fungi) are the physicality-animality based problems of survival, reproduction, nutrition, and self-defense. Lacking consciousness, these organisms don't create fictitious problems for themselves "out of thin air." A flower is not asking itself what is the best life for it or how it should dress today to impress local bees or whether it behaved badly yesterday. These "low-level" organisms have impressively solved the problems of survival, reproduction, nutrition, and self-defense for millions and even billions of years. Their problems- and the behavioral solutions to these problems- seem basic and elemental to us but we should not lose sight of how well they solve these problems over time spans much longer than the entirety of human existence. As just one example, mosquitos seem to solve the problem of nutrition without the corresponding problem of obesity.
(3) The problems of conscious animals excluding man are also largely limited to those of survival, reproduction, nutrition, and self-defense. A pug, for example, is also not asking itself what is the best life for it or how it should dress today to impress its owners or how can it improve its self-esteem. The pug dog knows what it must do to "get by." By providing its human owners with loving loyal attention, it will receive food, shelter, vet visits, and protection from hostile creatures that could injure or kill it "in the wild." The pug's behaviors are extremely limited (though very cute) but still these behaviors are well-suited solutions to the problems it "recognizes."
In a few highly conscious animals, certain other problems may arise that venture beyond survival, reproduction, nutrition, and self-defense. Issues of competitive dominance arise; certain emotions are experienced by a few highly conscious animals that need to be addressed; complicated group behavior "policing" may also be required. Not much is known in these areas so we will pass this area for now.
(4) The problems of man include the physicality-animality based problems of survival, reproduction, nutrition, and self-defense. These are physicality-animality based problems requiring physicality-animality based solutions. Man kills other creatures for food, chops up trees to build wooden homes, builds weapons to defend himself against other men and wild creatures, and engages in a whole host of mating behaviors which are essentially physicality-animality driven once the superficial veneer is stripped off (e.g. a man working hard to make tons of money to secure attractive female mates is basically doing animality).
A sober evaluation of the human condition reveals that the problems of man extend beyond the physicality-animality based problems. Most significantly, man confronts the twin problems of meaning and longing for a life somehow "better" than what he's got now. These are real problems requiring real solutions. Unlike other living species, man's actual solutions to these problems are neither identical nor equally effective; these solutions range from the most excellent and outstanding solutions to the stupidest solution imaginable. Of course, most solutions- and certainly most solutions mandated by social programming and conformity- congregate in the mediocre, trivial, largely ineffective, and banal area.
(5) More important than even this, man is pretty much alone in being able to create MANY problems out of thin air that simply shouldn't exist and that aren't really problems at all. Human DNA facilitates the human MIND which is the most unbelievable complicated machine known in the universe. For all its virtues, the machine of the human MIND can get sidetracked, lose its way, make spectacular errors, embrace stupidities as "supreme truths." Most of the time, this is done by the MIND creating and then wrestling for decades with a "problem" that is not even a "problem" to begin with.
This is one of the easiest ways for a human MIND to make itself miserably unhappy. Precious mental space, emotion, and resources of time/money are often devoted to problems that are not even problems to begin with. As but one example, many persons believe they must solve the problem of "a path to success," admiration and esteem from people you don't even know, and being somebody important and powerful in this world. Many others believe they must solve the problem of meeting someone to marry so that they can dutifully raise kids. These are not even real problems. The real problems are finding meaning and creating a better life for oneself. For certain persons, success, admiration, marriage, parenting, and all the rest may be solutions to these more fundamental problems; for most of us it isn't. But either way, these solutions should not be viewed as problems for all of us in that we must all seek someway to the same solutions. In this way, the problems that many human beings identify as eagerly important (e.g. how can I find the right person to marry?) to be resolved are not even problems to begin with. These persons are paving their own road to unhappiness by creating problems that should not even exist.
(6) Happy persons act in exactly the opposite manner. They distinguish between real and fake problems as best as they can (even happy persons are not error-less). The happy person doesn't see death at age 80 or 90 as a problem at all; having lived well, he sees this amount of time on Earth as sufficient to pursue and achieve most of the goods of value in life. Happy persons distinguish between problems of the self and the problems of others, particularly when those problems are caused by stupidity verging on outright insanity. They are not callous or insensitive to those problems but still recognize these problems as outside the self and largely out of their control. They distinguish between problems that have a solution and those that have no known solution (violence in the Middle East). Illusory problems are discarded from MIND and don't absorb any time, attention, stress, or concern. Real problems are focused on (loneliness, lack of friends, lack of money to ensure basic survival, obesity, stupidity, violent and other self-destructive tendencies, addictive vices) and solutions based in reality to these real problems are continually perfected by trial-and-error processes.