As far as professions go, it's fair to say doctors are among the most highly respected. And why not - they save lives, deliver babies, sign your passport and provide testimony in trials of the century. Of course, there are other incredible doctors who never even went to medical school. But that doesn't mean they don't know how to operate in their chosen field.
This week, as it happens, three of these "doctors" are celebrating birthdays. So, with that in mind, here are our favourite doctors who aren't actually doctors.
6. Dr. Doom - Henry Kaufman
No, we're not talking about Stan Lee and Jack Kirby's super-villain comic book character, who's battled the likes of X-Men and Spider Man.
This Dr. Doom is Henry Kaufman, an economist who earned the nickname in the 1970s and early 1980s when he was the top economic thinker at Salomon Brothers.
Kaufman made his name for his sobering predictions, that interest rates
would rise and bond prices would fall.
As The Economist puts it, Kaufman became famous for "his warnings about
the dangers of debt bubbles back in the days when today's doomster-in-chief, New York University's Nouriel Roubini, was still in short trousers."
5. Dr. John - Malcolm John "Mac" Rebennack, Jr.
A member of the Rock and Roll Hall of Fame, Dr. John is perhaps best known for his 1972 album 'Dr. John's Gumbo' and his wild theatrical shows. A songwriter, guitarist and pianist, he became a blues/jazz/pop/rock n roll/zydeco/boogie woogie pioneer.
Dr. John has recorded more than 20 albums, won six Grammy awards, and can count Mick Jagger and Eric Clapton among his fans. He even rocked out with The Black Keys at the 2013 Grammy Awards.
Born and raised in New Orleans, he named himself after a local 19th century voodoo practitioner - someone whose medical credentials you'd be loath to question, especially if you hate needles.
4. Valentino 'The Doctor' Rossi
Born on the 16th of February 1979, Rossi is one of the most successful motorcycle racers of all time.
A nine-time winner of the Grand Prix World Championships, he is second in all time overall motorcycle racing wins.
As for the "doctor" nickname, there are a few theories on how Rossi got it. Some suggest the name stuck after he earned a honorary degree.
Rossi himself has often joked that he got the name because many actual doctors in Italy share his surname.
3. Carl Hilding 'Doc' Severinsen
This doctor was a fixture on The Tonight Show when Johnny Carson was host from 1962 to 1992, and was known for his wild suits and flashy style. Severinsen became the show's bandleader in 1967, and under his direction The Tonight Show NBC Orchestra became the most famous big band in America.
A celebrated jazz trumpet and cornet player, Severinson got his nickname as a kid. His father was a dentist, and the folks in his hometown called him "Little Doc".
Over his career, he's released more than 40 albums and conducted several American orchestras, including the New York Pops at Carnegie Hall.
2. Dr. J - Julius Erving
Before Michael Jordan or Vince Carter or Lebron James, NBA legend Dr. J revolutionized playing above the basket with wicked rim-rocking dunks.
According Erving, the handle came about through back and forth ribbing with a friend, whom he'd nicknamed "The Professor".
Doctor caught on for Julius and after a storied career he was inducted into the Basketball Hall of Fame.
As Magic Johnson put it, "I remember going to the schoolyard as a kid...and everybody there would be saying, 'Did you see The Doctor?' And we'd all start trying to do those moves." Dr. J celebrates a birthday February 22.
1. Dr. Dre - Andre Romelle Young
Perhaps the most famous "doctor" in the world, Dre celebrated a birthday on February 18 and is one of the most influential people in the history of rap and hip hop.
He's often credited with bringing West Coast G-funk rap into popularity, and has produced and mentored some of music's biggest stars - including Eminem, 50 Cent, and Snoop Dogg.
Dr. Dre shot to fame as an original member of N.W.A. - one of the most iconic groups of the past 25 years - with the classic album 'Straight Outta Compton'.
Then, went on to huge success with his solo debut 'The Chronic' in 1992 before starting his own label as a record exec.
In 2011, Forbes magazine ranked Dr. Dre as the third richest person in the American hip hop scene with a net worth of $250 million Thankfully, this doctor ditched his old 'Master of Mixology' moniker, which sounds like he'd be responsible for umbrella drink concoctions.
Bizarre New Dr. Dre Video.