Narcissists, by definition, have an excessive preoccupation with themselves, a lack of empathy for others, and an inflated sense of their own importance. They tend to view other people as objects to be used for their own gratification and may have difficulty forming deep emotional connections with others.
While narcissists may not easily forget someone who they perceive as having insulted or challenged their ego, they can often discard people from their lives without much remorse if they no longer serve their needs or feed their ego. To a narcissist, relationships are often transactional, and they may easily move on to new sources of admiration and validation.
It's essential to remember that every individual is different, and there might be variations in how narcissists behave. Some may have a harder time letting go if they feel they are losing control over a person or if they have developed a strong attachment to them as a source of narcissistic supply (i.e., attention, admiration, or validation).
If you've had an experience with a narcissist and are dealing with the aftermath, remember that the best course of action is usually to focus on your own well-being and personal growth. It can be challenging to have a healthy relationship with a narcissist, as their behavior tends to be manipulative and harmful to others. Seeking support from friends, family, or a mental health professional can be beneficial in recovering from such experiences.