Today, President Obama's second swearing-in ceremony went off without a hitch. That wasn't the case last year.
Chief Justice John Roberts, who was administering the oath four years ago on January 21, 2011, botched it in a now-famously awkward moment.
However, it wasn't the first time that it happend. According to the collective wisdom harnessed by Wikipedia, at least, there were five other instances in which the presidential oath of office was bungled in some way.
The first slip was in 1909, when Chief Justice Melville Fuller misquoted the oath while swearing in William Howard Taft. However, it being before the age of mass media, no one really heard about it, "in those days...there was no radio, it was observed only in the Senate chamber," Taft wrote later.
Ah, the good ol' days.