Years ago when actors signed contracts to work for a particular studio and the studio system was much more controlled, an actor's age was pretty much whatever the studio boss said it was. Humphrey Bogart's birth date was listed as Dec 25, 1900 even though he was born in 1899. And Katharine Hepburn reportedly avoided questions about her age and was known to deduct two years off her real birth date of May 12, 1907.
But these days, any celebrity or celebrity wannabe interested in age altering has an increasingly tough go of it. Websites like Wikipedia and IMDb post biographical data for the world to see. Public databases do too.
And if everyone from your graduating class in high school is posting pictures from your 10th year reunion on Facebook, it's pretty hard to tell people you're still 18.
"These days you sort of have to seal everything at a young age and change your name if you really wanted to prevent someone from finding out your real age," said Jacobs.