I am twenty-six and since 1998 not a single year has passed that I have not played extensively, so no, you are never too old to play. However, it is a closet sport for me since it would have been socially unacceptable where I am - in sixth form, university and then at work. :/ There is nothing wrong with keeping it to yourself if it avoids lots of conflict/snide remarks, (personally it seems like they are missing out).
Some people have come out as Star Trek
fans so there is hope for this old nerd.