The alternative theory about celebrities such as Britney and Madonna is that they are largely "young souls", still relatively new from the source:
YOUNG SOULS

Having mastered the Infant and Baby Soul issues of survival, discipline and order, the essence is now looking to see how powerful it can become in the world.

Independence and the ability to get what one wants out of life are the driving force of the Young Soul stage. Seizing what the physical plane has to offer, vying to gain positions of prominence, power and great wealth, causes this to become the most competitive period in the whole cycle of lifetimes. Those who are expressing themselves from a Young Soul perceptivity will tend towards a sort of tape measure mentality that makes them monitor who among them has the hottest investments, the most lavish parties, the most important friends, the greatest weekly aerobic output, the tallest building, fastest motorcycle, broadest shoulders, thinnest hips or heaviest diamonds. The most powerful places in the world--Japan, Hong Kong, Germany, Israel, Syria, Saudi Arabia, Australia, Canada and the United States--all express a strong Young Soul perceptivity. Everybody growing up in these places, regardless of soul age, will receive Young Soul imprinting or conditioning about how to act, think, look, and feel in order to be a success. Japan is now the example par excellence of this: an extremely competitive, focused society where even having fun looks competitive. Often, there's no time off on the way up!

Ambition is important with the attitude being, "There is you and there is me, and I am going to win." There is a great drive to get ahead. In the process of getting to the top, it doesn't matter too much what needs to be done or who's stepped on or over.....
Because they are desirous of making something of themselves and leaving their mark on the world, Young Souls can be tireless workers. We owe them our efficiency, much of our high technology, our military might, and our continual push to make things happen and change. ....

Because Young Souls are not emotionally open, they tend to make poor parents who don't make strong feeling connections with their children. However they will buy their children everything they can afford. Like the prototype Yuppie baby in an Aprica stroller and exquisite French togs, children become status objects for their parents. These children with expensive toys, haircuts, cars and educations, will be pushed to excel in all they do from nursery school through college, to marriage and career. Those successes will reflect favorably back on the status-seeking parent. Children are not pushed to express their feelings.

Because Young Souls are heavily identified with their bodies and really not sure that consciousness survives it, we have cryogenic suspension; plastic surgery for noses and elbows, thighs and chins, breasts and waists; a booming multi-billion dollar industry devoted to beauty products for men and women; and an incredibly huge and costly (Young Soul, high-tech) medical system which intends on keeping everyone alive as long as possible regardless of desires, costs, pain, or quality of life.

As superb manipulators of the environment, humans are unequivocally good at the Young Soul phase. Winning out over rivals, gaining acclaim, power and money make them feel on top of the world. In spite of incredible stress--and fears about losing--this is an essentially exciting, fulfilling time. Because the earth just now completing its Young Soul phase, acknowledgement for Young Souls, who are already outgoing go-getters, comes along quite easily. Towards the end of the Young set of lifetimes, people will start to experiment more with food and sex. They'll likely become adventurous with extensive travel, both to experience the world, their oyster, and to gain status among peers.

Creativity begins opening up during this phase, although it comes to a fuller fruition in the Mature phase. Many, many people rise to fame and prominence during this period; we find movie stars, TV anchors, singers, comedians, politicians, executives, religious leaders, Nobel prize-winners, Hollywood producers, authors, and people like Donald ♥♥♥♥♥ and J. Paul Getty, who get so rich they get famous.....
http://www.michaelteachings.com/soul_ages.html#young