Softie or Cold hearted

When seeing me in the clinics, a lot of my frens think that I'm confident (at times) or overly stressed (at times)
For the most parts, I'm not really as stressed as ppl made it out to be.
Apart from the fact that clinics IS a more stressful environment (for us students who dun know what we're doing), that's just how I am when I dun smile.
Do u realise that when I'm not smiling I have a naturally sad/stressful/life-is-shit face ?(which I can also explain in terms of occlusion but I won't bore u with it) and its pretty damn hard to smile 24 hrs a day...so u get a lot of the non-smiling bits from me
In the clinics, I talk less, being more careful of what I'm saying in front of/behind pt and all
Wearing the mask didn't help. While my mouth was screaming "shittttt...pulpal exposure" silently, my eyes didnt give away much. All pt got was a blank look from me
I think it's part of the professionalism that has been taught/expected of us to behave in such a way
Interestingly I find that when seeing pt, students who put on a serious look may be viewed by patients as being more competent.
By that I mean. When we are being professional... not getting emotionally involved.... calm... we tend to talk less and just do our work. pt see that as a sign of confidence (being in control) and do respect us for it

but then again, lecturers do ram the concept of "communications" and "building up rapport" into our heads week in week out
Looking at my frens who talk a lot, pt do feel more comfortable around them but I feel that pt dun take those students as seriously and treat them more like kids.

Is pt's confidence in our skills or rapport more important?
Should I put on the face or talk more?