Empty Parachute theory

The empty parachute theory is when someone (can be boy or girl but is usually a girl in heterosexual relationships) dating a boy/girl feels that their being able to get said person shows that they are clearly destined for greater things (better people) so after a while they will dump said person and attempt to find someone else. After they are unsuccessful in finding/keeping a new relationship they will then attempt to go back to the first person, almost as if they had jumped off of a cliff when they broke up with them and now after realising they had no parachute (no chance with others) they are crawling back to the top of the cliff (Original person).

This theory is common in instances where the girl was shy but attractive and the boyfriend is average (or easily friend zone-able) but is friends with a lot of people. Once the girl has become part of his social group she might feel that she can do better and attempts to find others without realising that without dating said guy she doesn't have any sort of parachute and is back at square one (If not lower).

Tim: You know my ex Emerson who dumped me a month back? She asked me out.

Alexandra: Yeah obviously, it's the empty parachute theory, she thought getting you was good but thought she could get even luckier, don't waste your time.

Jacob: Michelle dumped Jim, I wonder why, they were so good together and he helped make her so many good friends.

Amy: Oh that's classical textbook empty Parachute theory. Wait 3 weeks and she will be begging for him back.