It's difficult for anyone to miss the fact that today is Lady Gaga's 25th birthday. Her own trending Twitter topic serves as a constant reminder. But who's actually surprised that the entire world keeps such a close eye on the Mother Monster? Her Little Monsters, which have developed into somewhat of a cult group sure to go down in history, have already immortalized the biggest pop sensation in the world. So, today, we're not just celebrating another ho-hum celebrity's birthday—we're marking another milestone in the career of the most provocative women in music. With your attention all over her now, go gaga over these pics of the most celebrated birthday girl in the business.