Context

This line is from the song "Papa's Got a Brand New Bag" by James Brown from the album Papa's Got a Brand New Bag (1965).

At first glance, you might think this song is about an old guy who's gotten a nice looking new handbag, but you'd be pretty wrong. In this case a "bag" is an interest (you know, how Austin Powers says, "That's not my bag, baby"). This old guy likes to hit the club and burn it up on the dance floor. He does the Jerk, the Mashed Potato, and the Twist.

James Brown is all about this old dog learning new tricks. Keeping breaking it down and shaking your groove thing, Papa. You're a dancing king!

Where you've heard it

This is a pretty famous song that changed the face of funk music forever, so we're guessing you've heard it quoted before. The idea that someone has a new interest isn't new to this song, but James Brown coined this exact phrasing, so if you hear that papa's got a brand new anything you can thank the Godfather of Soul.

Additional Notable References: 

• "Papa's Got a Brand New Bag" also appears in the movie Mrs. Doubtfire, but they mean it a little more literally with the handbag thing.
• A Simpson's episode was called "Poppa's Got a Brand New Badge."

Pretentious Factor

If you were to drop this quote at a dinner party, would you get an in-unison "awww" or would everyone roll their eyes and never invite you back? Here it is, on a scale of 1-10.

It's always pretty neat when an old dog learns new tricks. We don't think that's pretentious at all.