Mastering a Programming Language

To preface, I have been programming for the last 10 years with several years of employment through a variety of programming languages (C, Python, Go, and a couple more). However, I've realized that due to the breadth of my experience, I have never really gotten around to "mastering" any language. I feel like a jack of all trades, master of none. I find myself understanding all the concepts, but when it comes to specific languages, I rarely understand the