Credit: Photo via Instagram Photo: Porsha Stewart Rocks Ombre Hair

We've come to expect and kinda love Porsha Stewart's airhead moments on The Real Housewives of Atlanta, but she took her ditziness to a whole new level this season when she revealed that she thought the historic Underground Railroad was an actual, real, choo-choo train.

Porsha appeared on Andy Cohen's Watch What Happens Live this past Sunday, where she finally addressed her mistake.

"First I’d like to say when I watched that I realized that was another Porsha moment, a little airy there, just a brain lapse," Porsha began.

She then went on to assure us that she did do some research on the history of the Underground Railroad.

"I felt I definitely needed to correct that, even for myself. I went back and I just brushed up on what I already know. That’s a very sensitive topic for me … so I went back and I read up on the Underground Railroad and everything else because I do want to represent that part of my life and my legacy better than I did," Porsha added, referring to the fact that she's the granddaughter of Civil Rights activist, Hosea Williams.

"At that moment, we were all trying to figure something out and my brain was going so fast. It was just going faster than I was speaking so I literally just I couldn’t get it together at that moment. I went back and made sure I got my facts together," Porsha told Andy.

Regardless, that doesn't change the fact that her brain told her that it was a real train.

What do you think of Porsha's embarrassing flub? Check out the clip and sound off in the comments below!