The fundamentals of linear algebra and statistics are indeed quite easy to understand. Common concepts and algorithms such as cosine similarity and k-means are

The fundamentals of linear algebra and statistics are indeed quite easy to understand. Common concepts and algorithms such as cosine similarity and k-means are very straightforward. Seemingly arcane mathematical notation is what frightens off beginners in many cases, though. Once you've understood that - for instance - a sum symbol actually is nothing else but a loop many things become a lot easier. However, the devil's in the details. Many edge cases and advanced methods of machine learning are really hard to understand. Moreover, when 'good enough' isn't just good enough any more things tend to become very complex very quickly.