A disciple is a follower or a fan of someone. You might consider yourself to be a disciple of your favorite yoga teacher.
The noun disciple comes from the Latin word discipulus, which means "student, learner, or follower." One of the earliest places disciple showed up was in the Bible, where it means "a follower of Jesus," sometimes specifically one of the twelve Apostles. It's still used that way in religious speech and writing, but it can also describe a serious, dedicated follower or student of a teacher or leader.