When
you practice zazen you will of course have physical pain in your legs and
mentally you will have some difficulty. You will find it difficult to be
concentrated on your breathing. One after another images will come into your
mind or your mind will go out for a walk and wander about. I have many
difficulties in my practice, so I think you, too, will find it very difficult
to sit in good zazen.
Excerpt from Shunryu Suzuki lecture 65-12-11A as found on shunryusuzuki.com. Edited by DC