A 20-year-old college student underestimated the power of the internet — and now she has to go to class dressed like a Christmas tree for a week

© Provided by Business Insider Inc girl tree- On Saturday, Kelsey Hall wrote on Twitter that if a picture of herself dressed in a Christmas tree costume got 1,000 retweets she would wear the costume to class for the rest of the semester.

- The tweet went viral, reaching over 1,000 retweets in one day.

- So far, the 20-year-old University of Alabama student has kept her promise to wear the costume to class.

- She wrote on Twitter that this is her "biggest regret in life."

On Saturday night, Kelsey Hall, a student at the University of Alabama, jokingly tweeted a picture of herself in a Christmas tree costume along with the caption, "1,000 retweets and I'll wear this to all my classes for the rest of the semester."

The 20-year-old college student told BuzzFeed news that she didn't think anything would happen, but her tweet unexpectedly went viral.

Within one day, Hall's original post had surpassed her goal of 1,000 retweets, sealing her fate.

Luckily, Hall only has to wear the costume for a week, as classes at the University of Alabama end on December 8. Still, she wrote on Twitter that this is her "biggest regret in life."

Hall told BuzzFeed news she decided to keep her promise and find the positive in the situation.

"I'm like, 'Oh man I have to do this all week.' I followed through with it," she said. "It's right before finals and everyone's stressed out about studying, so I thought this would bring them some joy and make them laugh."

To prove that she's actually wearing the costume, Hall has been documenting her week on Twitter.