Pattern is something that you see EVERYWHERE. Not only art, but in nature, architecture, product design, even science! Why do you think that they stress learning patterns as early as kindergarten! It is important!
Finding pattern in photography is not hard, it just takes a little extra intentional observation. Take a leaf for example. Any leaf will do. Look at the way that the veins on a leaf. Notice how they methodically trace themselves back to the central vein and into the stem. That’s pattern!