system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is it so hard to get over things? Like breakups?
gpt
There's a part of your brain called the amygdala that links emotions with memory and decision making. When your brain is recording memories, the amygdala can color that memory with the emotions you are feeling at that time. Stronger emotions can lead to more powerful memories.

When you do have those emotionally charged memories, anything that reminds you of those memories will cause you to feel those emotions associated with it. In terms of a relationship, you have spent so much time together that many of the daily things you do are colored with emotions. When you break up (break ups can also be very emotional to give you another strong memory), all those daily things that you still do are now tinted with emotions and memories of your ex. This can lead to a spiral where thinking of memories of your ex reinforces the emotions of wanting to get back together (despite the reason behind breaking up in the first place).

This is why to get over a breakup, people often change themselves (new haircut) or change part of their lives so those emotional memories will fade in intensity. It also helps to get rid of objects that remind them of the previous relationship.