I'm not saying some is fully developed mentally as a teenager. But people constantly dismiss ideas or suggestions from people younger than them... because they are younger. I really wish I hadn't let 'grown ups'(family, public school teachers... people who were neither very smart nor successful) brow beat me into thinking I was stupider than I actually was.

You are right. I guess the ideal is a bit of a balancing act. To embrace the advantages of youth - you are not so solidified, you can try things your elders might not dare or consider - but to remain humble and know that you have a lot of growth ahead, admitting that you haven't yet reached the peak.

Suddenly I remember why teenage years were so hard.