[tboyd47]

You never really master it. The key is to get comfortable enough with a popular technology that you don't struggle to complete your daily work, leaving your mind free to approach higher-level problems.

I got there with Rails after about 2 years of training, self-study, and the right work environment. I haven't been able to repeat that success, although I have been exposed to one or two out of these three with many other languages and tools. I think all three must be present at once to really feel that sense of mastery. Training for the theory, self-study for the practice, and work environment for the application.