Yeah, I think I've been all of those different descriptions at one time of my life or another. When I was young, I was super quiet and had terrible self esteem. But I think that was influenced a lot by the people I was around. Then I went to college and it took 4 years of making presentations and an acting class before I felt less self-conscious around people. I still am pretty quiet at work when I'm concentrating. Then I start goofing around with a coworker and my INTj boss makes comments that my personality is schizophrenic. (Would you prefer I be loud all the time? Is that what you're looking for? 'Cause I can accomplish that if it would make you happy...Having a 'supervisor' as your boss sucks sometimes)

I think now I come off pretty consistently as 'cheerful, and laughs a lot.'