The good news is the creature shares with the "Trill" (which is really a humanoid shell), a wealth of life experiences and knowledge. The bad news is "Dax" the symbiote is over 300 years old and has made a number of Klingon friends. When Kang, Koloth and Kor come looking for their ol' pal Curzon-Dax, (previous host and creature) they simply couldn't believe their eyes. I guess you might say Jadzia is the ideal fix for a new life in the "witness protection program." Apparently Jadzia studied all her life to become a brilliant scientist and have a slug stuck inside her. Its the greatest honor a trill can give.
Trill long and Prosper, trekinators.