Milk is very good and nourishing, but when it is touched by the mouth of a snake it is no longer nourinshing; rather, it becomes a source of death. Similarly those who are not strictly in the Vaisnava discipline should not make a business of Srimad Bhagavatam and become a cause of spiritual death for so many heares.
One achieves bhakti [love of God] by hearing and chanting about the Supreme Lord's special qualities, even while engaged in the ordinary activities of life in this world.
Loving devotional service to the Lord begins with hearing about the Lord.
Srimad Bhagavatam 1.7.7,
If we chant and hear enthusiastically, then memory will come.