I'm 23, and have a Tanzer 8.5. Bought my first "real" boat (Tanzer 22) at the age of 19.
My fiancee and I are definitely the youngest ones at our yacht club, but we do find we have a lot in common with other older members when we start talking to them.
One thing that we've noticed, however, is that people are in disbelief when they talk to my fiancee and hear about all the fiberglassing, grinding and restoration work she does on our project. Admittedly more than I do, because my time in the office limits how much I get down to the boat