PEOPLE Magazine 40th Anniversary

Look Who's Turning 40

From Leonardo DiCaprio and Victoria Beckham to Hello Kitty and Happy Days, see who's celebrating the milestone with PEOPLE

POST-IT NOTES

Romy and Michele attempted to claim that they invented the handy pieces of sticky paper, but it was 3M scientists Arthur Fry and Steven Silver who were the actual inventors. Created in 1974, the adhesives didn't hit U.S. shelves until 1980. Four decades later, they remain the most recognizable scraps of paper found in any office.