From: http://mirrorofthesoul.blogspot.com/
30 is a great age.... you can date an incredibly sexy 40 year old woman AND her 20 year old daughter, if you choose. And...women hitting their 30s are far more interested in sex than those in their 20s (their hormones begin to shift and their testosterone level begins to rise to one hundredth of man's, but it is enough to make her far more randy in her 30s than her 20s -- so say the researchers.)
It is the last decade before little physical problems begin to creep in, but not horribly so. The knees are still good, but you notice them. Wholesale slowing down is still decades off but staying up two days in a row become a little harder. And in a few years you're eligible to be president.
If I had to choose an age to go back to, and to stay permanently, 35 would be it. No longer a youth, but not aging either. It is a time when one starts to become internally settled, one begins to know who you are, and 20 year olds start to become kids. Thirty really is a good age. Indeed, the 30s are much better than the 20s. Your adventure is just beginning.