I think it is important to reveal the parts that taught you something, that had an impact on your life in some way, and of course anything that has an impact now. If a previous lover didn't really have these effects on you and there's absolutely no bearing on your life now or who you are now, then there's nothing to be gained by divulging the information. I know for me it's been very helpful to know some of the details about how a previous wife or girlfriend treated my husband and some of the major issues they had, because then I not only know a little better how to deal with it when problems arise, I also have a much better understanding of where he's coming from on various issues. For instance, he's very touchy about arguments that escalate into yelling and such and would never tolerate anything being thrown, but because I know that a previous girlfriend stuck a fork in his back during a fight that he had to get the neighbor's help to remove, then that makes sense for him to be so touchy and I take extra care to stay calm. That said, it would be of absolutely no use to expect him to go into intimate details about those relationships that is really none of my business...it's good to know he likes something, but there's no need to know who showed it to him first. All I need to know in that respect is that those relationships are long over.