There was a difference between Bharata Mahārāja’s acquiring a deer body and others’ acquiring different bodies according to their mental condition at the time of death. After death, others forget everything that has happened in their past lives, but Bharata Mahārāja did not forget. According to Bhagavad-gītā:

yaṁ yaṁ vāpi smaran bhāvaṁ tyajaty ante kalevaram taṁ tam evaiti kaunteya sadā tad-bhāva-bhāvitaḥ

“Whatever state of being one remembers when he quits his body, that state he will attain without fail.” ( Bg. 8.6 )

After quitting his body, a person gets another body according to his mental condition at the time of death. At death, a person always thinks of that subject matter in which he has been engrossed during his life. According to this law, because Bharata Mahārāja was always thinking of the deer and forgetting his worship of the Supreme Lord, he acquired the body of a deer. However, due to his having been elevated to the topmost platform of devotional service, he did not forget the incidents of his past life. This special benediction saved him from further deterioration. Due to his past activities in devotional service, he became determined to finish his devotional service even in the body of a deer. It is therefore said in this verse, mṛtam, although he had died, anu, afterwards, na mṛta janmānusmṛtir itaravat, he did not forget the incidents of his past life as others forget them. As stated in Brahma-saṁhitā (5.54) , karmāṇi nirdahati kintu ca bhakti-bhājām. It is proved herein that due to the grace of the Supreme Lord, a devotee is never vanquished. Due to his willful neglect of devotional service, a devotee may be punished for a short time, but he again revives his devotional service and returns home, back to Godhead.