You do not have to believe that all of the world's suffering is your own in order to still desire to stop all the world's suffering; I commend you if you have this desire regardless!
However, some people are too habitually selfish ever to have this intrinsic respect for everybody else unless they see everybody else as
themselves, and these same people, unfortunately, are most often unwilling or unable to adopt this new perspective.
Plus, even with no desire to harm, people still are sometimes unaware
of the suffering they cause for others.
These problems, along with all the other problems in the world, is due to our egoic separation: the fact that each of us is only directly aware of
his or her own life. Because each of us is only directly aware of his or her own life, each of us, at least sometimes, is liable to disproportionately focus on promoting his or her own happiness (as opposed to the happiness of others who may be in greater
need) and liable to disproportinately adhere to his or her own beliefs (as opposed to the beliefs of others who may understand better). Thus, whenever people lack empathy for each other or are ignorant of each other's better understanding, this is because
of our egoic separation, and one or both of these two factors—people's ignorance and lack of empathy—can be found, in some way, to cause and/or worsen every one of the world's problems.
Our egoic separation, then, may be illustrated like this, where the the larger brain represents those who understand better and are in greater need: