Why Patterns?
Patterns are common “Recipes” to solve recurring problems. They are proven solutions that have been tested and refined over time.
Patterns allow us to save time, because if someone knows the pattern, then you do not need to explain. If everything in the universe must be explained, you end up with slow progress.
There are many patterns out there, some are better than others, some are very specific to a domain or problem. Other patterns are like a Swiss army knife that can be applied in many different situations.