What Is Your Mastery?

Quincy Jones said his career did not start until he did Thriller with Michael Jackson at age 50. The other 49 years were preparation for a moment to work with an artist who would do all styles. Jesus, we don't see him again for 18 years but could it be that the 18 year hiatus was there so he could develop mastery? We're discounting what God is counting on by saying you have stopped going when you're older.