The self-proclaimed experts really muddy the waters. As do those seen to be experts by virtue of their charm, charisma, fame, or actual expertise in bullshitting. Another issue is those who claim to be or are judged to be experts in one field by virtue of their legitimate expertise in another.

I think there are actual experts as long as we're willing to define the term in a way that doesn't confer wisdom or in relation to what remains unknowable. For me, a true expert is someone who knows more about something than the vast majority of people, is continually striving towards expertise and mastery, and can explain things to those with little or no expertise.

Also, I think expertise is a range, not an absolute. It's completely reasonable to accept the expertise of your local accountant without also thinking that they could be the CFO of a Fortune 500 company.

For myself, I try to embrace the unknowns as new adventures or ignore them as irrelevant to the task at hand. I don't know why there are so many joinery techniques in woodworking or how to choose the most appropriate for a particular situation, but I'm having fun learning. At the same time, joinery is irrelevant to many of my projects, where doing everything by eye with scraps on hand using nails and screws gets the job done quickly and effectively.