The Lord never suggests anything impractical

He does not advise Arjuna simply to remember Him and give up his occupation. No, the Lord never suggests anything impractical. In this material world, in order to maintain the body one has to work. Human society is divided, according to work, into four divisions of social order—brāhmaṇa, kṣatriya, vaiśya and śūdra. The brāhmaṇa class or intelligent class is working in one way, the kṣatriya or administrative class is working in another way, and the mercantile class and the laborers are all tending to their specific duties. In the human society, whether one is a laborer, merchant, administrator or farmer, or even if one belongs to the highest class and is a literary man, a scientist or a theologian, he has to work in order to maintain his existence. The Lord therefore tells Arjuna that he need not give up his occupation, but while he is engaged in his occupation he should remember Kṛṣṇa (mām anusmara (BG 8.7)). If he doesn't practice remembering Kṛṣṇa while he is struggling for existence, then it will not be possible for him to remember Kṛṣṇa at the time of death. Lord Caitanya also advises this. He says, kīrtanīyaḥ sadā hariḥ: (CC Adi 17.31) one should practice chanting the names of the Lord always. The names of the Lord and the Lord are nondifferent. So Lord Kṛṣṇa's instructions to Arjuna to "remember Me" and Lord Caitanya's injunction to "always chant the names of Lord Kṛṣṇa" are the same instruction. There is no difference, because Kṛṣṇa and Kṛṣṇa's name are nondifferent. In the absolute status there is no difference between reference and referent. Therefore we have to practice remembering the Lord always, twenty-four hours a day, by chanting His names and molding our life's activities in such a way that we can remember Him always.