I've always been more comfortable being an observer than being observed. I've spent most of my adult life being some form or other of an audience member. This isn't to suggest I'm reserved - I can be very out-going, although I find almost all socializing exhausting, even when it is a positive experience. I need a lot of down time.
It is interesting now that I've become the one that puts myself out there to be observed. I find it really rewarding, but at the same time it is, just like the socializing above, exhausting. I guess everything exhausts me. Life exhausts me.
It also fuels me and energizes me - I just need that resting period.
I need that time to observe.