If we have a strong sense of love for the Supreme Lord, then we can discharge our duty and at the same time remember Him. But we have to develop that sense of love. Arjuna, for instance, was always thinking of Kṛṣṇa; he was the constant companion of Kṛṣṇa, and at the same time he was a warrior. Kṛṣṇa did not advise him to give up fighting and go to the forest to meditate.