I grew up with a narcissistic mom. Naturally, I knew nothing of my self-worth or what I wanted and needed. I did not have the chance to develop an inner voice. The narcissistic parent tends to undermine that.
They don’t do it consciously, I don’t think. Still, the result is a kid, then a teenager and finally a young adult, who does not know what’s going on inside of them. It might seem like they do, but important feelings, needs and wishes are buried deep down.