Competence and Confidence are two words that come to mind. Like you, Neil, I make my contribution very much "behind the scenes", and leave others to be the "the front men"! That's always been my
forte, and has worked well enough in some of my previous lives.
As Huw would say, I'm not a "face"! But (to be fair) there are other people about who excel at being up there, on the podium (on the stage, at the lectern, whatever).
When it comes to "teaching", I guess I could do it in the formal sense if I simply followed a script, but
ad-hoc (or off the cuff) would be no good in my case for two reasons:- 1) I would always have doubt in my own mind that I
really knew my stuff, and 2) I have a tendency to jump (grass-hopper like) from one "topic" to another as my thoughts dictate (that's just how my mind works).* It can sometimes be great fun when I'm with like-minded people (
aka, friends) but would most likely be a bit frustrating for students! Ha, ha.
I prefer "mentoring" ... kind of a quiet, one on one thing. That's nice too, as it leaves me clear to cuss when cussing is required! But yes (like you I suspect, Neil) ... I'm actually more use when I'm putting in the hours, left to my own devices (could that be a pun?). Most biomeds whom I've known and respected have been like that. What I call "quietly confident".
But "fair do's" to Brian (Rob Strange, and others ... Vaughan Pretlove is another who comes to mind) who can stand up there and keep the class entertained for days, without resorting to utter [censored]! Especially, that is, if I'm sitting there, plonked in the back row (and have been known to complain - afterwards - when I had discovered that my money had not been well spent)!

*
Remember James Burke's "Connections"?