i have played with a Dom in the past that was actually trained as a sub, for a year, before changing to Dom. (i don't consider him a switch because once he changed over, more then 18 years ago, he hasn't subbed again.)

i always felt, that because of that experience he understood the pain factor better and therefore understood my needs/levels better.

Could i inflict the pain on another. i can... but i don't enjoy it. Push me far enough though and i will do it just to prove a point if nothing else... the entire time hating the fact i am doing it. (Even being a Domme to hellish and michebe in the cellar was a push for me... lol).

Someone once told me that it takes a special mind set to be a Sadist... inflict pain on the one you love and still be able to look at them over the breakfast table the next morning without regret...