How many times do we not move on or accept things? More than we need to, I think.
This life is meant to be lived and enjoyed. To do that you have to move on from things that are upsetting, accept the things that change around you, and trust that all these things will make you a stronger and more complete person.
All of life teaches you lessons and those lessons make up who you are as a person.
Hopefully, they make you stronger and more complete.