Elena woke slowly, regretting all the drinking she had done the night before. Her head was pounding, and she wished she hadn't celebrated the New Year quite so much.

That thought brought a frown to her face. Thinking back, she hadn't had that much. She had stopped partying hard years ago. Then, the memory of Caroline and Stefan surfaced, and she wondered if she was mistakenly equating a tension headache with a hangover. The problem was that it absolutely felt like a hangover.

She rolled to her side and pulled the covers up over her head. Through her headache, she wondered how she got home last night. All she could remember was walking away from the party and then she was waking up in her bed.

Reluctantly, she sat up and thought about making some coffee. She hoped that would help her feel better.

Opening her eyes made her scream out in complete panic. She wasn't at home. She was in the apartment she lived in years ago before she was married.

Elena whipped off her covers and got up quickly, instantly regretting it. She had to dash for the bathroom, barely making it in time and heaving in the toilet.

As she held her hair back, trembling from the shock and from vomiting, she turned to the mirror. She looked younger —crap. She then washed her face and brushed her teeth, setting her toothbrush to the side to be tossed unless she threw up again.

After returning to her room, she grabbed her iPhone, which looked old to her. She held the small device, scrolling through her apps, trying to figure out anything she could. She next pulled up the search engine and Googled, "What year is it?" Elena had watched plenty of television shows about time jumps. No matter how ridiculous it sounded to her, there was only one explanation for why she was back in her old apartment with all of the things she had back then.

Tears pricked her eyes when the search results returned, "Wednesday, January 1st, 2014."

"Well, shit," Elena mumbled and sat down on her bed, clutching her phone so hard her knuckles turned white.

A large smile spread across her face as soon as it dawned on her that it meant she wasn't even engaged yet. She could avoid a marriage fraught with her husband and one of her closest friends hooking up for years.

Her mind raced thinking about that. Caroline and Stefan had already been sleeping together from what she had overheard. A tear leaked down her cheek, thinking of the betrayal she had unknowingly endured for a decade.

"Never again," she vowed to herself.

Then, despite her hangover, she pushed through it, brought up a blank document on her phone, turned down the brightness to spare her head, and started typing. She wrote all the events and important dates in her life moving forward. She didn't want to forget anything.

Once that was done, she lay down and wept bitter tears. She had reflected on how so many moments were now tainted by the possibility that Caroline and Stefan were cheating on her. Even if she was right about the fraction of all the random memories she had where the two of them disappeared together, she had been cheated on a lot.

She set down her phone and closed her eyes. Her hangover from her past self's previous New Year's celebration had become too much to bear. Before she drifted off to sleep, she thought about how she was glad she kept a diary. She would have to read it to remember where she was in her life. Ten years back was a long time to remember.

She had the iPhone 5S, which came out in September 2013. This means that for her to have an iPhone on New Year's Day 2014, assuming she didn't have the 2012 iPhone 5 model, it had to be a brand new phone. The first iPhone came out on June 20th, 2007.