Exercises - learn by doing

Lots of people have already requested more exercises.  I find that the way to really learn a problem. Most courses/books have some sort of 'code along with me' example, but a learner needs some exercises to do from scratch.  (The Wrox books used to be particularly good at this).  These exercises take time to think up and put together, so you could ask other people to submit exercises and sample solutions for each pattern, much like the Codewars site has user collaboration for the content.