Justin Timberlake says of Madonna:

"She's the most stubborn woman in the world. As a woman, she's the highest in stubbornness. But she's very smart and incredibly cerebral. And I think that's why she's been able to change her style and image so much. Her music pays attention to what people are thinking." 

Interesting quote, though it almost reminds me of that fake "tip-top starlet" satirical interview by Garry Trudeau that eventually became wrongly attributed to Madonna thanks to his odd "she's the highest in stubbornness." Teen idols never went to school, so any who are as bright as Timberlake otherwise seems to be probably have genius-level IQs.