But I still am puzzled. As a Mac user since 1985, I would like to ask if we have to have virus protection software for PC since I have not had any onto my Mac's still now.
I'd strongly recommend having virus protection for any machine running Windows. Because Windows has a much higher market share than other operating systems, it gets attacked far more often. Mac viruses and trojans do exist, but they are rarer.
I've read varying opinions on whether OS X or Linux are "inherently more secure" than Windows. I have my own opinion as well, but as long as the attacks are so heavily skewed towards Windows any inherent difference is of less importance.
"There is no real magic in photography, just the sloppy intersection of physics and art." — Kirk Tuck