There are people who, when when asked a question, will answer to you:
"If I have to explain it, then you couldn't possibly understand it."
They are usually jerks who think they are part of some elite group, of which you are not welcome as a member. They are also often completely wrong in their own understanding of whatever you asked about.
The quote concerning comdom use falls into the same category as the answer above.
There are two classes of people who might falsely believe in the condom quote:
1) Those who are already HIV positive, believe there is no further risk to anyone because they have sex only with other HIV positive people.
This is false thinking, although many, many people do it. A friend of mine believed this. He was poz for years, but quite healthy. He had unprotected sex with other poz people. One day, he gets "superinfected," that is, gets infected with a second, different strain of HIV than the one he was so sucessfully combatting. With in a matter of months, his health changed entirely. His focus on life changed from "I'm going to live a long time and do great things" to "Go away and leave me alone while I die."
2) Those who are so naive to think that someone they do not know particularly well is telling the whole truth about their health and sexual history, or even knowns all the correct information.
