Singer Joe Jonas.
Singer Joe Jonas in Aug. 2011. Reuters

Happy bday DJ Danger! That short sentence trended worldwide for 12 hours on Twitter Wednesday, but it left many people scratching their heads wondering just who the mystery character is.

Oddly enough, it turns out that DJ Danger is an alter ego of boy band star Joe Jonas, who turned 23 on August 15, and apparently set the social media world on fire with messages of congratulations for living another 365 days.

Not to be confused with DJ Danger Mouse of Broken Bells and Gnarls Barkley fame, DJ Danger is apparently a reference to a number of times when Joe Jonas referred himself to Danger and DJ Danger. For instance, a Jonas Brothers YouTube clip shows Joe Jonas joking about how dangerous he is for committing the superstitious faux pas of opening an umbrella indoors.

Despite the fact that the trivia about his name is clearly a little-known fact for people not familiar with the wildly popular boy group, Twitter still came alive to wish Joe Jonas a happy birthday all day on Wednesday.

Twitter user @LoveNickJonasBR showed some love on Wednesday by tweeting the following message, which repeated the common sentiment that Joe Jonas is growing up too fast:

"@joejonas i remember you with 18 years old.. and now you're with 23, PLEASE, STOP GROWING! Happy Bday Dj Danger."

And he got love from a whole range of countries around the world, according to a tweet sent out Wednesday by @JonaticasMEX that was accompanied by a birthday video made by some of his biggest fans:

"@joejonas Happy Bday Dj Danger DE FANS RUSSIA HappyBdayJoeFromRussia"

Though he still isn't old enough to rent a car on his own (he's got two more years until that's an option), Joe Jonas himself was clearly moved by the bday wishes, as he responded to all the love and retweeted some of the most choice messages that people sent him to help him ring in the big 2-3.

For instance, Joe Jonas retweeted the birthday shout out he got from his fellow band member and brother, Nick Jonas:

"love you duder! @nickjonas: Happy birthday to my best friend and brother@joejonas"

And the hospital where he was born -- Casa Grande Hospital in Casa Grande, Arizona -- even apparently named their baby hospital after Joe Jonas, according to a touching, personal tweet he sent out from his Apple iPhone:

"My Mom and I sent cupcakes from @sprinklesAZ to @casagrandehospthe place I was born! They named the baby hospital after me.. So cool!"

So it seems that it's a good 23rd birthday for DJ Danger. And many more...