> I hope that every year of my life, I look back, and laugh at the things I 'knew' 10 years ago.
You know what? I never did do that, and I'm starting to think I never will.
There may be many 20-year-olds that "knows" many things (in the same scare quotes you indended), but there are a lot of 30- and 40-year-olds who do that as well. I have a growing suspicion these may all be the same people...
The oft-repeated idea of an "underdeveloped" teenage brain is a bit old. Scientific American did a piece on it in 2007. (http://www.scientificamerican.com/article/the-myth-of-the-te...)