The King very much regretted having left his Queen and having gone to the forest to execute sinful activities. When a person regrets his sinful activities, the abandoning of Krsna consciousness and good intelligence, his path of deliverance from the path of material clutches is opened. As stated in Srimad-Bhagavatam (5.5.5): parabhavas tavad abodha jato yavan na jijnasata atma-tattvam. When a person loses his Krsna consciousness and loses interest in self-realization, he must engage in sinful activities. All ones activities in a life devoid of Krsna consciousness simply lead to defeat and misuse of ones life. Naturally one who comes to Krsna consciousness regrets his previous sinful activities in the human form. Only by this process can one be delivered from the clutches of nescience or ignorance in materialistic life.