I have been to international congresses with international speakers and amazingly some of these speakers did not know how to speak.
I have attended high profile meetings and amazingly the chair person of the meeting did not know how to chair a meeting
I could go on like this about so many things, people do and quite a number of them are not prepared.
There are books written about virtually everything. We do not have to start any of our tasks from scratch. We can benefit from the trials and errors of others and from the wisdom of experienced people. When we read these advices from the so called experts with a critical mind we can often distill gems of wisdom from so many books. I was lacking all confidence for public speaking until I read a book about it. I was not capable of chairing a meeting effectively until I read a book about it.
Perhaps the big exception to this is parenting. I did not know how to parent effectively, I read many books about it and I still don't know how to be a real good parent. I want so much to be the best parent in the world, but I tend to fail so often. Perhaps the most helpful book I read regarding this was titled: how to talk to children so children will listen and how to listen to children so children will talk. They have a variant to it for teens as well.