The meaning of "handle the uncertainty of not being convinced that they know everything they ought to do and say"

Question

I'm studying English and I'm reading a book how to improve your English. The writer said that those who study English should approach foreigners to improve English. After that, he write:

Most students do not dare to approach foreigner at all, often because they are afraid to look like an idiot. Their confidence is too low to handle the uncertainty of not being convinced that they know everything they ought to do and say, and they have such low regard for themselves. However, it is much better to take action and risk looking like an idiot with a chance of improving your English than not to take action and clearly demonstrate that you are an idiot with no chance of improving your English.

I know "uncertain" means "not sure", and "convinced" means "completely sure about something",but I still don't understand the sentence, especially the expression "handle the uncertainty of not being convinced that". Can you help me? Thank!

Answer 1

This is not a very well-written sentence, but it's not too difficult if you break it down into pieces.

Their confidence is too low to...

Their confidence is so low that they can't do something. What can't they do?

...handle the uncertainty of...

They can't manage, or deal with some kind of uncertainty. What kind of uncertainty?

...not being convinced that...

They do not firmly believe that something is true. What is it that they do not think is true?

...they know everything they ought to do and say.

So the whole sentence could be rephrased like this:

Their confidence is so low that they can't approach a foreigner. It is low because they cannot deal with being uncertain. They are uncertain because they are not sure of something. They are not sure that they know exactly what to say.

The reason I say that this is not a very well-written sentence is because it's too long and wordy. When you break it into smaller pieces, you realize that "the uncertainty of not being convinced" is repetitive - if they're uncertain, that means that they're not convinced, so it doesn't make very much sense to say that they have the uncertainty of not being convinced.