Miley Cyrus pens thank you note to Hannah Montana on show's 15th anniversary

Miley Cyrus gave "Hannah Montana" fans the biggest surprise for the show's 15th anniversary. The internet was hard at work trying to figure out why Hannah Montana suddenly joined Twitter and Instagram earlier this week. Many then pointed out the fact that the show premiered 14 years ago on March 24. Now Miley is joining in on the fun by writing a special note to Hannah after all these years.