Alhaitham's circle of close friends and acquaintances was VERY closed; His list of "bearable people" included: Kaveh... And other people.

He tended to be very jealous, and even possessive, of the few people he considered his friends. One day in the morning, the gray-haired man was with a good acquaintance of his, reading together in the library.

"You are the most jealous man I know." — His partner commented laughing.

"You know any more jealous men other than me?!" — He said.