One becomes dear from a sufficient cause. One becomes an enemy from sufficient cause. The entire world of creatures is actuated by the desire of gain. One never becomes dear to another without cause.
कारणात् प्रियतामेति द्वेष्यो भवति कारणात्॥ अर्थार्थी जीवलोकोऽयं न कश्चित् कस्यचित् प्रियः।