It's rare, but being highly passionate and exuberant doesn't directly point to mania.
There are people whose baseline mood is around hypomania on the mood-scale but they're not ill, whereas a diagnosis of unipolar mania definitely crosses the line between normal and abnormal.

Seriously, read 'Exuberance; passion for life'
http://www.amazon.com/Exuberance-Pas.../dp/0375701486