I had a client some years ago who was a real Captain Know it All. I still cannot fathom why he chose to instruct us.
among other things, he argued that neither I, nor his barrister, knew anything about the ears of law we were dealing with. He knew better because he had read 'a law book' in the library. He maintained that position even after being shown the relevant statutes and case law...
(I have to admit, I did lose my temper with him at one point. He'd just spent about 20 minutes trying to convince me that we were wrong, and he was right, about a fairly basis piece of law relating to his case. In support of his argument, he came out with "You haven't even read any law books, have you." I'm afraid I answered "No, I spent 4 years at university getting a degree and postgraduate qualification in law and never once read a single book about law. Then I spent a further 5 years specialising in this area of law but never read anything on the subject"
Bizarrely, he shut up after that. At least until the next time we saw him.
(He also couldn't understand that even if he had been right about public funding being available to sue someone for libel (it isn't) and it had been possible to sue someone for libel for things written in correspondence subject to legal privilege (it isn't), or worth while to sue someone who has no assets (and no platform to repeat their comments), the fact that the statements you are taking exception to are in fact entirely true, easily provable and relate to things you yourself have already admitted to doing would make any libel case extremely brief..)