Another thing about design patterns – each author has a different description.
Some describe it in 2 paragraphs or a 10-line example using one dog/cat class. Others write 3 pages and 5 classes. Yet others write a whole chapter on it in a design pattern book.
If I go by the simplistic interpretation to describe a pattern, then the interviewer may think I don’t really know it.
If I give an in-depth example, then it could be too complicated to describe (I’m not extremely good at describing complexity) and interviewer may not be an expert on that pattern to understand me.
My suggestion is to focus on 1 or 2 patterns. Understand them inside out and also remember some simple examples in your own app. Our knowledge of a pattern should grown from thin to thick to thin, yes back to thin. Only when we have a streamlined understanding can we describe it with clarity.
Here are some complex patterns I have struggled with for years – visitor, bridge, strategy, composite, chain of command, memento, command, observable …. Each of them can be summarized in 1 paragraph, but let’s be honest – these aren’t simple.