Even when people sympathise with them, they always bear in mind that they are often rich children, who live in comfort.

comfort 是名词，意思是"舒适、安逸"，指生活条件优越、没有困难或痛苦的状态。这个词来自动词 comfort（安慰、使舒适），描述一种身心愉悦的状态。