A girlfriend of mine encouraged me to watch this video of Meg Jay (clinical psychologist), for Ted Talks, discussing the significance of the age of "20's".
If you are in your twenties and have the time, I highly recommend you also watch this video, too! Dr. Jay presents the importance of why individuals in this age group should avoid the reckless, thoughtless, and careless choices. Life decisions and habits made during these times are a huge precedent for lifestyle and qualities of one's 30's, 40's and beyond.
I loved this as it reinforced everything I try to work towards in my life. Plus, I get geeky with information and facts related to psychological development. :)