Am I at risk for a sexually transmitted infection (STI/STD)?

Are you sure it's an STD? How did I get it?  I don't understand, I didn't have sex with that many people. During my work as a disease investigator, I consistently (for over fifteen years) got the same few questions over and over again. It shouldn't surprise me, humans find it difficult to personalize and connect their own behaviors. I think it is just the way we're wired. When I would ask someone to tell me what behavior put them at risk for certain diseases, most people can recite it backwards. Smoking leads to emphysema, alcohol abuse leads to liver problems, obesity leads to heart attacks, and unprotected sex leads to STIs/HIV. Of course, not everyone who smokes a pack a day will have lung problems. Just like not everyone who has unprotected sex will get an STI. But, one in four people will. It will probably be chlamydia, HPV, herpes, or trichomoniasis. That is just statistics talking. But nobody really expects it to be them. And, even when they know they are doing something that puts them at risk, it is still hard to conceptualize personally. Which is pretty obvious when you look at the numbers. My experience taught me that most of infections were not due to lack of knowledge, but a lack of the ability to personalize the knowledge. That is why doctors get addicted to pain pills and yoga instructors wind up with acute stress disorder. Right? We all know better, but that doesn't matter. Knowing and believing are two entirely different subjects. This became apparent early in my career. After every sex ed spiel I gave, someone would approach me and ask me about their specific situation. I found myself saying, "well, except for the hair color..."  and "Yes, just because it was the back seat and not the bed...", or "just because he initially had on a condom but hen it miraculously disappeared" Same basic rules apply to us all. So the infamous question for me is not how to we educate people, but how can we get people to personalize their risk? I am not sure, and I am not going to try to be a behavior change extraordinaire. I too, am human and lack the ability to personalize. That is why I kept asking how the heck I gained ten pounds in two weeks over the holidays? I know I ate fudge, four holiday dinners, a few pies, and tons of other yummy gooey gourmet goodies that melt in your mouth, and in your hands (while waiting to be shoveled into your mouth).
My experience has taught me that the greater the health outcome, the more likely a person is to change the behavior. There is a significant difference when talking to a newly diagnosed HIV positive person and someone who just found out they got chlamydia. I use that example because both infections are usually asymptomatic. So, it is not the physical symptoms felt at the time of diagnosis. I believe some of it is fear based. After all, one is life-changing and one is freak out today and I'm so over it tomorrow. I am sure there are many ideas out there. I would love to hear others opinions, experiences, and stabs in the dark. Please, do tell. But, don't ask me about a particular evening in May with a brunette. Please.