She's just being Miley...
Miley Cyrus, born November 23rd 1992, was introduced to the world as Hannah Montana. Miley found fame in the show that took the world by storm (the world = Disney fans under the age of 12) and has since become a musical star in her own right.
The single See You Again from Meet MIley Cyrus became her first top 10 single in 2007, then came the powerhouse singles The Climb and 7 Things, that led to the release of Breakout, an album which stood completely unconnected to Hannah Montana. The album hit No. 1 and was certified platinum.
If that wasn't enough, the starlet broke into the film industry, starring in films Bolt, LOL and Hannah Montana (duh!) and is subsequently engaged to hottie Liam Hemsworth, with all the on-and-off drama that so often comes with young love.
She was the richest teen in Hollywood, and now as she enters her 20s with a feisty new image and a hot new sound, the world is truly her oyster.