How is one supposed to be compassionate and 100% free of suffering while others are suffering?

How is this possible besides if one simply doesn't mind if others are suffering? But if one truly doesn't mind whether others are suffering or not isn't that a lack of compassion? Is one supposed to let go of compassion regarding others? Even if there is nothing that one can do to help the other being, even if one is doing one's best, wouldn't the desire to end all suffering for all sentient beings still be present and therefore suffering still existing in one before that goal has been achieved? I don't see how it is possible for a being to be compassionate and free of suffering while still knowing that others are suffering. Is it supernatural? Does it transcend reason?