The obvious flip side of health is illness. Illness and even disability are not always as apparent as many people would expect. The people taking the elevator up one floor? They're called lazy, which they may very well be. But they could also be recovering from a leg injury, suffering from debilitating back pain, or simply having an extremely difficult day.
Instead of considering the alternative possibilities, people frequently assume the worst about others. Instead, we should remember that not all illness is apparent to our eyes, nor should obvious illness be the only reason for our compassion.