i belive that you get into the life of bdsm though life experences, subconsinsly. If you were hit as a kid or bullyed, or got bossed around, you'd probllay turn into a submissive like it or not. That isent to say your sexualy a submissive, but more of a giveing "nice" person. Same with the oppiset if your spoiled or popular and stuff like that you become domenent.
Really this is more of an educated guess then fact though.

When i first relized I was a submissive, is when i was 12 and this bully girl told me to get down and like her boot. at fist i dident but her frends made me, and as i was doing it ohh your god i felt good, at the time i had no idea. After that i tryed to make girls hit me and tese me, fun stuff.
Just to protect my ego, If kids picked on me one on one i'd fight and usauly won.