Confidence

The woman from the job agency gave me a call earlier and said she'd put me forward for a temp job in Angel. She rang back a couple of hours later to say the place liked my CV and asked me to come for an interview at 11am tomorrow, which is today as I'm writing this.
On the phone, the agency woman said to me make sure you are confident in the interview, shake the guys hand firmly, look him in the eye, speak loud and clearly etc.
It got me thinking, I just can't do any of that, I can't be loud and confident and walk into a room and be like "HI, MY NAMES ANTHONY, HOWS EVERYONE DOING HERE!?".
There are some people that are like that naturally, they can just talk like water from a tap on demand. I always try and do it, and I just end up feeling stupid and go even quieter than before.
People sometimes perceive me as moody and quiet, I'm really not, I just like hearing people talk, and often don't have a relevant point to interject on.
Ah well, what a goth, hope the interview goes well, I could be starting Monday!