Like a lot of this section of the course on of the elements that are the subject of this exercise is often incorporated in shots on an almost subconscious level. In other words the shot is taken and it is only afterwards that, on further deliberation, you have included diagonals, verticals, curves and rhythms as well. Patterns are I think, as far as my shooting is concerned, a more conscious choice and I think the reason for this is that patterns have a danger of being a boring composition unless, like the example in the coursebook, you have something to break it up and or add extra information to the shot.
I looked through my past shots and its very hard to spot any pure pattern shots and had to think for some time before I came up with the shot below.
Rhythm on the other hand is an easier spot. The Calke Abbey shot below was taken with this exercise in mind (along with several others) and was not a hard shot to identify (and I would have taken it anyway without the exercise at the back of my mind), the same going for the other examples shown.
I was thinking about what this says about me as a photographer. I concluded that maybe I just do not like the order that is, normally, inherent in pattern shots but prefer and identify easier the randomness of rhythm.