I later met other black Americans who had spent years in Africa studying Islam.
Non-Muslim students in private schools are not required to study Islam.
They say they came to live in Afghanistan to study and practice Islam freely, but some clearly took up arms as well.
The section was usually full, and women there formed groups to study Islam.
One of the factors for this change is the influence by members of their family who have gone abroad to study Islam.
Hasan refuses, then devotes himself to studying Islam with his father.
And I spent the next 20 years studying Islam on my own.
In 2004, he travelled to Egypt and lived there for a year to study Islam.
But some of the several hundred young men who studied Islam with him say they have no such qualms.
While in Mecca his father arranged for him to study Islam as well.