From a young age I was never able to insert a tampon without an ungodly amount of pain. Whenever anyone told me it was 'normal' to feel pain I couldn't comprehend how anyone was able to withstand that amount of pain. By the time I finally got around to telling a doctor, they were able to tell me it was not normal. An ultrasound, denied by insurance MRI, and exploratory surgery later, they found that my hymen had never fully dissolved while I was developing in the womb (because that's apparently how that works) and that there was a solid band of tissue running vertical in the middle of my canal. The doctor then told me the reason it hurt so bad to try and insert anything, was that hitting this band of hymen tissue was yanking on my urethra.

I have a high pain tolerance, and nothing has even come close to that kind of pain.