Bob and Hannah were friends for a long time. They were neighbors and went to the same school and were mostly all good buddies for a long time and just accepted being boyfriend and girlfriend. Bob had adjusted the watch a little and then made eye contact with Hannah and instead of seeing her eyes saw her neck along with a little bit of cleavage that wasn't there before. She was now 14.
Hannah said "Nice watch Bob. Now the hardest part of that problem is just trying to figure out a common denominator. Here's a trick. Multiply the 20 and the 7 together." Bob took up his pencil and wrote down 140 and then Hannah said "Good, now the number over what the 7 was should also be multiplied by 20, and the number over the 20 should be multiplied by 7."
Bob sighed writing everything down and then muttered "So many steps."
Hannah chuckled and said "I thought the same thing, but most of this is pretty easy once you see the patterns and that's what i'm trying to help you with. Seeing those patterns." Bob remembered Hannah being the same age as him, but now he also remembered that Hannah was 2 years older. They still had fun together every now and then during parties however only recently she had started helping him with some homework problems. Bob sighed and twiddled with his watch a little wondering if girlfriend Hannah was just his imagination and then noticed Hannah's cleavage start to grow a bit then noticed Hannah start too look older. who sighed and said "Where the heck are you looking kid?" Bob gasped a little and accidentally hit his watch and noticed Hannah's boobs grow further as she matured and her clothing changing then noticed that Hannah seemed to have vanished. Then he heard T.V. being played and looked and saw the young adult Hannah watching the history channel who glanced over and asked "Finished with your math homework or need some help?" although it sounded like she didn't want me to bother her. His memories of "older sister" Hannah ended as "babysitter" Hannah memories start to surface. she was 6 when bob were born and when they were together she always looked over him but generally found he was more of a nuisance. Now she was babysitting for a little bit of extra money but she was barely doing anything so it was basically her lounging around and stepping in if something goes terribly wrong.
Bob sighed and went to the bathroom and then looked at the watch and thought "It was you that did this wasn't it... maybe if I turn it back..." he then fiddled with the watch and...