Ah yes, I see what you're talking about, as I am 14 myself. However, I do see why most (older) people think that. It is because most of us are not as mature as we consider ourselves, just as many of the others on here have said. Like say, even one year ago, when I was 13, I considered myself pretty... If there's like a medium between immature and mature that's leaning more on the mature side that would describe it, but now that I look back, I see the stupid things I've said, the stupid things I've done, which all sounded good to me back then (although I'm kinda thinking now everything sounds better to themselves than it actually does). And then of course, there are also the people that fit that stereo type exactly. And for most people, it's not the good things that stick in people's heads, but the bad things. I remember when my band did something really stupid at the family night and our band director was lecturing us about this she used the example of how even if our school made hundreds of awards and such, but then there was a shootout at our school, which one would people remember more? It's a mix of these things that cause adults or older teens (who actually could still fall into the immature category, not trying to call any of you out though) to ignore our opinions. Also considering the fact that many people (not limited to any age group) are very... biased and one-sided and won't look at the bigger picture or accept others opinions, and the fact that this is probably even more prevalent in the teenage group, it causes people to ignore their opinions since pretty much the teen is already ignoring theirs. I wish too that the stereotyping wouldn't exist, but it is pretty much guaranteed to unless all teens somehow magically become... open-minded I guess and more stable in controlling emotions. Just keep trying to show that you're different than others then I guess, if you really are, then older people (the ones that don't act like the stereotype at least) should start accepting your opinion, or at the least hearing you out.