I think a second dimension on this discussion would be fascinating. "How old are you AND how old do you feel?" Although I'm not sure how to word that just right.

For instance, capturing situations like: Are you a 65 year old grandfather that feels younger through the interaction with the core crowd here? Are you a 12 year old aspiring hacker that seeks the maturity of the seemingly 20-something base contrary to the peers of their own age?