I used to enjoy self-inflicted pain back when I was younger and single, for a variety of reasons. Some times it was to punish myself for actually having masochistic fantasies or for becoming sexually active. I guess some of it had to do with my self image. But ultimately I did it because of the plesure it gave me.

Some of it was mild: self bondage, wearing very tall and tight high heeled shoes, etc, but eventually it was not enough and I went to more severe self-discipline such as pouring hot wax on my breasts, taking showers with scalding hot water, kneeling on gravel, hanging weights from my pussy lips and stuffing my bra with thumbtacks.

Now that I have a partner the idea of doing it to myself seems pointless, but the memory of the pleasure I got from it can not be erased. Also, on the plus side, it built my resistance to pain, which my boyfriend now finds quite impressive.