First let me say that I am no expert on narcissism and only have knowledge from reading and my own experience. I understand that narcissism can be passed along in families, but not because it acts like a virus but because family members are conditioned to maintain the same delusions with each other. This common façade is what I understand to be the cause of generational narcissism. I see the same tendency in my family.
But narcissism is only self denial so if a person is open to seeing other possibilities and their own issues, I do think narcissism can be eliminated. It is more a matter of ignorance than anything else, IMO. The problem is that as people get older, they are less prone to accept alternate viewpoints and instead stick with the opinions they have held for years. So admitting fault and confronting themselves is difficult.
My mother has spent her whole life wrapped up in her fantasy world. At this point (she is 72 years old) she is not too willing to re-evaluate her flaws. I have argued with her directly on this point, even telling her that she is simply scared to see herself and admit to how she has affected others. Her reply is that others should be accommodating her and not doing those things that make her made (and other countless deflections).
When she was younger, I think these same issues triggered fights between my parents, but she still had the optimism of youth to offset this. As she got older, the outlook for future happiness began to grow dimmer, and as more and more people distanced themselves from her or began to stand up to her, she began to grow bitter. As she pulled into her shell, she would focus on herself and find friends who would give her the feedback she wanted (narcissistic supply).
For instance, she has a nice Japanese styled house overlooking the lake and somehow the local Republican party got in touch with her and asked her to hosted a few political fund raisers. Needless to say there was all sorts of praise for her and the house, thanks for hosting the party, etc. Nothing wrong with that per se, but she selectively filters those who give her the ego boost she wants to replace what she has lost with her own family. So in a way she digs herself deeper into her self deception because when family confronts her with her issues, we stand in sharp contrast to the praise so many others give her, so there must be something wrong with us, not her.
I don’t know if this answers your question, but unless you go into a cave, I don’t see how you could ever become narcissistic.
