Something funny happens to you on the "expert" side of the Dunning-Kruger curve and it has probably happened to you at some point or another.
As you gain proficiency and practice and experience and knowledge and time in a field... basically, as you gain expertise you start to recognize, more and more, just how little you still know about your field. What's more, as things become easy and second-nature to you, you start to assume everyone around you must also recognize how easy and second-nature it all is.
As was first attributed to Socrates, "I am wise, for I know that I know nothing." Or as you might hear pop scientists like Neil deGrasse Tyson or Brian Cox talk about how they are happiest when they can either disprove a theory and go back to the drawing board or prove one... that just leads to more questions.
So now there you are, at your job, where you have been promoted to whatever position you hold because the people around you have faith in you (or, perhaps, because you poisoned the previous person in that position... different companies work in different ways). And you're called into a meeting or you're called in to give a presentation to some clients or something. You sit down, the meeting is about to start, you lay out your notes or whatever, and you look around the room, and you're hit with this feeling:
"What the fuck am I doing here? I'm surrounded by some of the best people in the organization, maybe some of the best people in the field. And they're going to ask ME questions about this shit?!? That's just idiotic! How do they all not recognize that I'm just the same dork I was in the 7th grade? I'm not even a grown up; for dinner last night I had Doritos and ice cream."
It's called Imposter Syndrome. And it manifests in funny ways.
Let's talk diving.
"You need to do things my way, because my way is the absolute best way and you'll probably spontaneously combust, yes... even underwater, if you don't do it the way I do it."
Yep, that's some posturing bullshit. Often it comes from someone who insists on a single way of doing things simply because that's the way they were trained and they just don't know another way. But it is just as frequently from someone who does know a bunch; someone who finds themselves in a position where they are looked to as an expert.
But that someone knows they are the same dork they were in 7th grade, who would rather be home binge-watching Family Matters and discussing the finer plot points with the doll their daughter always leaves on the couch. So what they'll do is throw out their chest and play the part of the expert to the fullest; they push through it and hope that by projecting that image of absolute self-assurance no one will catch on to the fact that they're a fraud.
Please do not misread this: I am not accusing anyone of being a fraud. Quite the contrary: I am pointing out the sometime silly behaviors we participate in even when there is a level of expertise.
Here's another one, different side of the same coin (or perhaps the same side of a different coin):
Said in response to nearly any diving practice no matter how obviously cockamamie, "Whatever... if it works for you I guess that's fine."
No. Sometimes it isn't fine.
Sometimes, as an expert, one assumes that everyone they talk to knows all the things they know, has seen all the things they have seen. They make the false assumption that people are making informed decisions based on common sense. And they know they're the same dork from 7th grade who still makes up little dialogs for groups of ants like an idiot when they see them on the sidewalk. "So," they come to the conclusion, "Who am I to correct anyone on anything?"
I admit... diving is far more replete with the former. I struggle more with the later. Which is not to claim absolute expertise. It would be false modesty to say I lack any expertise at all; but I have been doing this a while and have reached a place where I look at the people around me, finding a peer group I respect enormously, people I continue to learn from constantly. And I certainly think to myself, "Sooner or later they're all gonna catch on."
Perhaps one of the reasons I like teaching as much as I do is because it's all so much more clearly defined: "I know things and you're paying me to tell you those things." It's pretty cut and dry. But I had a moment a few years ago that I try to keep fresh in my memory to remind me that, even in a teaching capacity, not everyone is operating with the same information set. It was an Open Water class. One of my students raised their hand on night one and asked, "You keep saying 'gas.' You mean 'air,' right?" I didn't realize I was doing that, and in so doing causing confusion. What you have in your tanks might vary, right? Might be nitrox, might be trimix, might be oxygen... I suppose it's conceivable that you could be breathing air. So you talk about "gas." But this room full of people who had just finished their eLearning... they didn't know that. Of course they didn't know that. (I mean, after about another 30 seconds THAT class knew that, along with every one of my OW classes afterwards.) Hell... even now I don't even know what I'm talking about. I suppose the point is: If you feel, in your heart-of-hearts, like you can talk about a subject with absolute authority - you're probably full of shit. If you feel, in your heart-of-hearts, like you need to ask a lot more questions and learn a lot more about the topic - you're probably in a good position to start passing things on. As a secondary point I have never seen a single episode of Family Matters and I don't talk to ants. Those were random examples. I have, however, read THIS anecdote by Neil Gaiman which is arguably the best example of Imposter Syndrome conceivable.