At the time of death King Purañjana was thinking of his wife, and this is called polluted consciousness. As Lord Kṛṣṇa explains in Bhagavad-gītā (15.7) :

mamaivāṁśo jīva-loke jīva-bhūtaḥ sanātanaḥ manaḥ-ṣaṣṭhānīndriyāṇi prakṛti-sthāni karṣati

“The living entities in this conditioned world are My eternal fragmental parts. Due to conditioned life, they are struggling very hard with the six senses, which include the mind.”

The living entity is, after all, part and parcel of the Supreme Spirit, Kṛṣṇa. In other words, Kṛṣṇa’s constitutional position and the living entity’s constitutional position are the same qualitatively. The only difference is that the living entity is eternally an atomic particle of the Supreme Spirit ( mamaivāṁśo jīva-loke jīva-bhūtaḥ sanātanaḥ ). In this material world of conditional life, the fragmental portion of the Supreme Lord, the individual soul, is struggling due to his contaminated mind and consciousness. As part and parcel of the Supreme Lord, a living entity is supposed to think of Kṛṣṇa, but here we see that King Purañjana (the living entity) is thinking of a woman. Such mental absorption with some sense object brings about the living entity’s struggle for existence in this material world. Since King Purañjana is thinking of his wife, his struggle for existence in the material world will not be ended by death. As revealed in the following verses, King Purañjana had to accept the body of a woman in his next life due to his being overly absorbed in thoughts of his wife. Thus mental absorption in social, political, pseudoreligious, national and communal consciousness is cause for bondage. During one’s lifetime one has to change his activities in order to attain release from bondage. This is confirmed in Bhagavad-gītā (3.9) : yajñārthāt karmaṇo ’nyatra loko ’yaṁ karma-bandhanaḥ. If we do not change our consciousness in this life, whatever we do in the name of social, political, religious or communal and national welfare will be the cause of our bondage. This means we have to continue in material, conditional life. As explained in Bhagavad-gītā (15.7) , manaḥ-ṣaṣṭhānīndriyāṇi prakṛti-sthāni karṣati: when the mind and senses are engaged in material activities, one has to continue his material existence and struggle to attain happiness. In each and every life one is engaged in the struggle to become happy. Actually no one in this material world is happy, but the struggle gives a false sense of happiness. A person must work very hard, and when he attains the result of his hard work, he thinks himself happy. In the material world people do not know what real happiness is. Sukham ātyantikaṁ yat tad buddhi-grāhyam atīndriyam (Bg. 6.21): real happiness must be appreciated by one’s transcendental senses. Unless one is purified, the transcendental senses are not manifest; therefore to purify the senses one must take to Kṛṣṇa consciousness and engage the senses in the service of the Lord. Then there will be real happiness and liberation.

It is stated in Bhagavad-gītā (15.8) :

śarīraṁ yad avāpnoti yac cāpy utkrāmatīśvaraḥ gṛhītvaitāni saṁyāti vāyur gandhān ivāśayāt

“The living entity in the material world carries his different conceptions of life from one body to another as the air carries aromas.” If the wind passes over a garden of roses, it will carry the aroma of roses, and if it passes over a filthy place, it will carry the stench of obnoxious things. Similarly, King Purañjana, the living entity, now passes the air of his life over his wife, a woman; therefore he has to accept the body of a woman in his next life.