Our mind is attracted by so many things, especially in the material world. When yoga system was advised to Arjuna that "You concentrate your mind upon Me," Arjuna flatly declined, "My dear Krsna, I cannot concentrate my mind in any particular thing." But he said that "I have got my mind on You." That is different thing. "But if you ask me to concentrate, it is very difficult for me."
Lecture on Bhagavad-Gita 7.1, Fiji, 24 May 1975