You are not a troublemaker

and it isn't your, or anyone's, age. Fishyfanatic is right; the title is based on your post count. They don't "mean" anything other than a fun way to group post count categories. Here is a list of the titles and the number of posts required to achieve that title:
Aquarium Advice Newbie - 0
Aquarium Advice Apprentice - 10
Aquarium Advice Regular - 50
Aquarium Advice Activist - 100
Aquarium Advice Freak - 200
Aquarium Advice FINatic - 500
Aquarium Advice Addict - 1000