Despite my crippling fear of aging, I can honestly say, objectively speaking, that 29 (30 in a few days) is not Old.
Aaliyah, though she meant in the opposite way that I mean it, was right, though--"Age ain't Nuthin but a Number." While she meant it in such a way that someone as young as her could be more mature than her age states, I understand it to say that age can be more a feeling than a number.
Exhibit A: A student of mine wrote on his recent final exam that he greatly enjoyed a certain book we'd read in class, a book whose setting was the student's hometown in the early 1990s. He remarked that the book "was great because it described our town how it was like back then (emphasis mine) when we weren't born yet?"
Dang...1992 was "back then?"