Partners develop shared friends, activities, and values, which all contribute to self-identity and self-concept. So when the relationship ends, the part of our self-concept related to our partners seem suddenly ripped away, leaving a void. We might look in the mirror and ask: who am I? Who am I without you?
In their research “Who Am I without You? The Influence of Romantic Breakup on the Self-Concept,” Slotter, Gardner, and Finkel found that due to a partner’s influence, your self concept clarity often decreases, while emotional distress increases.
In fact, the study found that a "significant amount of the distress experienced by individuals whose relationship ended was predicted by the self-concept confusion they experienced after the breakup - beyond the distress caused by other aspects of the breakup, such as self-rejection."
And we see it in everyday life. In order to get rid of the “shared’ self-concept, many people often change their hair, clothing style, or find new activities or hobbies. However, sudden changes in behavior and parting with a previously established self-identity can easily lead us to a feeling of emptiness and confusion—is this really me? Who am I without you?
So how can we preserve our self-concept clarity without being overly reminded of our ex?
One idea from the study is to participate in activities you shared with an ex with other friends, to reassure yourself that your interests are of your own even without your partner. You can then keep the hobbies you enjoyed doing with your ex, without being too uncomfortably reminded of him/her.
As for changing fashion or hair, it's a normal sign of beginning again. But maybe try doing these things with your friends, which will make the experience not a loss of your previous self, but a novel experience with a friend that can affirm your sense of self!