A series of problemsWhen a problem X happens during your day you naturally do not feel great about that. If the problem cannot be easily solved this unpleasant feeling can persist during your day and keep asking for your attention. But if suddenly another problem presents itself, problem Y, this new problem will seize your attention and emotion. You now will feel unpleasant about this new problem. But, at the same time, problem X fades into the background. You will think less about problem X and the negative feeling you had about it had also become less intense or even completely goes away. Next, you may encounter a third problem, problem Z, and the process repeats itself. Now, problem Y may fade into the background and problem Z grabs your attention.
PerspectiveMy impression is that when, later, you will focus again on problem X or Y, you will be better able to put those problems into perspective. They will then be less likely to elicit intense emotions and it will may be easier to focus on solving them. The fact this this is just a problem in a series of problems puts them into perspective. If problem A would have remained the only problem of the dat this may not have happened. Perhaps, you would then have had the opportunity to keep on ruminating about it. Perhaps you might have viewed it as a bigger problem in that case. Thus, it might be not such a good thing to have only a few problems.
VitalityI have occasionally wondered about the amount of responsibilities some people seem to be able to handle. Each day, the American president, for example, is confronted with a series of problems. These are not minor problems. They are usually the kind of problems which reach the president because they could not be solved at a lower level. I have wondered how it is possible that an American president, in such circumstances, can sill be energetic and positive. Obama, roughly my age, appears more vital than me, when I have so much fewer responsibilities and macro-problems to solve.
There are, of course, many possible explanations for this. But one partial explanation may be the mechanism I described above. Precisely the fact that your confronted with many problems may make it easier to put each of these problems into perspective and thus make them bearable. I surmise that having too few problems is not good for you.