If you have never had any sexual encounters of any kind before is it possible to have an STI?

Do coldsores mean that you have Herpes? My friend told me that coldsores were a sign of an STI. I had my first coldsore when I was 9 years old and I was definately not sexually active. I haven't had one since but I am afraid that I might be carrying Herpes. I know lots of people who get coldsores on a regular basis and I just don't understand how all these people could have Herpes. I know that it is very contagious. Does having this mean that you can never have sex? Can you clarify for me? Thanks a bunch!