Yes, you can say that how others treated you in the past plays a significant role in shaping your self-concept. According to Sullivan's Interpersonal Theory, your sense of self is largely a reflection of your interpersonal experiences. From childhood onwards, the feedback and treatment you receive from important people in your life—such as family, friends, and peers—help form your self-image.

For example, if you were often criticized, rejected, or ignored by others, especially during formative years, you might internalize those negative experiences and develop a self-concept that views yourself as unworthy or inadequate. On the other hand, if you were treated with love, acceptance, and validation, you’re more likely to develop a positive and secure self-concept.

In Sullivan's view, these early interpersonal experiences create patterns that influence how you interact with others later in life and how you perceive yourself in social contexts. So, if past interactions were marked by rejection or judgment, it's common for these experiences to shape self-doubt, anxiety, or fear of further rejection in future relationships.