To quickly be an expert write 50 lines of code everyday

At first glance it seems difficult for some or counterproductive for others. But that's what I'm doing for the past 12 months. Before the day starts, look at some code and augment it or at least delete it then replicate it. It doesn't matter the language, it doesn't matter if you are going to do Code Reviews all day and actually you will remove code. Just do it.