A pattern is a stable arrangement of something over time. In this context we are looking to describe our inner emotional world, and external social context in terms of regularly repeating patterns of thoughts, feelings and behaviours.
A pattern, apart from the term's use to mean "template", is a discernible regularity in the world or in a manmade design. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometric shapes and typically repeated like a wallpaper - wikipedia