Age doesn't play into it as much as maturity. I see immature posts by people in my age group (over 40) as well as those that haven't reached adulthood yet.

From my perspective, when I see someone with a insecurity about being listened to, ie they don't think people take them and what they say seriously, a lot of the time I conclude they are kids, and looking at the previous thread on age, I am usually right. Usually these people aren't taken seriously, IMHO, because they don't know how to express themselves in a way to elicit serious consideration of their ideas.