But how can you take someone at all seriously when it's clear that their response is merely from a frightened and immature insecurity?
Since it is from insecurity it loses all validity and should be ignored for what it is, right?
My experience has been that when people really need the answer, they listen because they are getting something they truly want.
Good question. Actually, my example of my own father illustrates the point pretty well.
You're young and somewhat insecure yourself. Your dad rejects what you are saying as a joke and as puffery. This is an authority figure talking down to you, telling you that your knowledge is not helpful and is suspect.
This comes up fairly often in the workplace. When it's an employer or boss, they may not have that emotional primacy, but they have the authority to brand your knowledge that steps on their toes as subversive, bad, destructive, suspect, dangerous, etc.
If it's a peer coming out of left field dissing what you're saying then of course you can tell them to F.O. and consider the source. That does not work so well for an authority figure, even for a weak one like a technical lead that management listens to over you. When you consider the source and it's an authority figure, then you have to comply.
An authority figure is most destructive when they are weak, and insecure. And you know they're never going to admit it, right?