Much like 'resonate', 'authentic' is a word often used in common parlance these days. It is thrown hither and thither until, to be honest, it becomes a bit smelly and tawdry. Whether something is authentic or inauthentic, just the mere fact of using that particular adjective in front of any noun precludes me from being interested in whatever other words should follow.
Before going any further, I'll mention that I started on this train of thought after Gi and I were talking about a childhood friend of hers. Long story short, we were both struck - suddenly and, therefore, quite forcefully - by his inauthenticity. He is not a bad person. He's likeable enough and very talented at what he does, certainly talented enough. But when we compared his success in a given field with another friend's success in the same field (same town, similar age, a lot of similarities between them), the key difference seemed to be how they expressed themselves. One was able to do it authentically, and had a following for his work. The other - to us, at least - wasn't, and is always struggling. So, maybe it isn't just us, after all.
Not being authentic is a massive barrier to achieving personal success. People, it seems, can smell it even if they can't see it. Take someone - anyone - a loudmouth 'bullshitter' (we've all known a few of those in our time), who is clear and honest about who they are and what what they are offering means to them. Despite not necessarily agreeing with them, and perhaps despite not actually liking them, we may gravitate to them far more readily than an earnest well-meaning individual who is not.
So, perhaps this is the truth of the matter and, actually, is belief in oneself. In the case of our inauthentic friend, perhaps inauthentic should be replaced with lack of belief in oneself. This would certainly be plausible in his case, for a few reasons. Taken wider, though, lack of belief in oneself might just be the biggest barrier to personal and professional success; the biggest barrier to not connecting with people, and the biggest barrier for people, actually, switching off. But it might not be wearing the clothes of timidity and, therefore, we may not see if for what it really is. This guy is not lacking in confidence, but maybe he's lacking in the confidence to be all that he is, to fully incorporate himself into his work. Certainly, that could be the case for many of us who have struggled with projecting ourselves in our work (and our work in ourselves).
Of course, some will always find it harder to believe in themselves than others, and for most of us who have ever been there, it is often easier to be inauthentic than to break cover and learn how to believe in yourself.