4. Expose Your Ignorance

I think there should be more separation between exposing your ignorance within fellow workers and the customer.

Consider the machine service technician who arrives at a job and promptly announces:

"I've never worked on this kind of machine."  Heshe might be the most experienced person within 50 miles and fully capable of analyzing the problem, getting the parts, and repairing the problem.  But feels obligated to announce their ignorance, even when it is not important.

The customer just doesn't care what your level of competence in your profession is - they care about their own problems.

I'd suggest that it is required that you expose your ignorance about the customer's problems - asking questions so that you can understand their problems.  But pointless to even mention what you know about programming the solution.

I think exposing your ignorance to the customer is a act of responsibility. Being honest about your skills with your customer (and with yourself and your colleagues) fosters collaboration.

If the technician mentioned above doesn't know how to operate the referred machine, he should make it clear to his customer. Along with that, he would tell he has a proven portfolio of achievements and he surely can handle the task. But he would have to read the manual or make some experiments.

You should not hide problems from your customer. And it is a customer's duty to decide what to do.