My perceived age seems to vary.
Most recently, just a couple weeks ago, I was told by several people I know from Habitat for Humanity that they all assumed I was between 30 and 32. When I informed them that I just turned 27 this February, they were surprised. One of them suggested that the goatee makes me look more mature.
During my last semester of college, at age 22, several people said that they would not even think I was 18 yet if it were not for the goatee. (I first started growing it earlier that semester, as a bike accident required stitches on my chin and I couldn't shave the area for a couple months.)
People thought I looked a year or two older than my age when I was a college freshman though.
As a high school senior, people thought I looked a year or so younger than I was.
As a high school freshman, upperclassmen kept forgetting I was a freshman and said I seemed old enough to be at least a Junior if not a Senior already.