What I have also found is that once you are a seasoned programmer and know 1 or 2 programming languages it doesn’t take much other than understanding the syntax and the specific language idioms to get up and running and the quicker you do the quicker you start to be able to write something worthwhile,
Cheat sheets are my way of learning a language, and they are also useful when I have to pick up a language after a period of non-use. I start with the basics and create a list of all the syntax and idioms that I need to know up to an advanced level. I can check back if required, or quite often have them open in another window as I code.
My current list of sheets and those in progress can be found at cheat sheets