They talk around in a circle, repeat and repeat, because, when they want a particular word to convey their exact meaning, they cannot find it.
If you are ambitious to talk well, you must be as much as possible in the society of well-bred, cultured people.

If you seclude yourself, though you are a college graduate, you will be a poor converser.
We all sympathize with people, especially the timid and shy, who have that awful feeling of repression and stifling of thought, when they make an effort to say something and cannot.

Timid young people often suffer keenly in this way in attempting to declaim at school or college.

But many a great orator went through the same sort of experience, when he first attempted to speak in public and was often deeply humiliated by his blunders and failures.

There is no other way, however, to become an orator or a good conversationalist than by constantly trying to express oneself efficiently and elegantly.
If you find that your ideas fly from you when you attempt to express them, that you stammer and flounder about for words which you are unable to find, you may be sure that every honest effort you make, even if you fail in your attempt, will make it all the easier for you to speak well the next time.