Should it matter to you how many people your bf/gf slept with?

So I had a girlfriend who was very promiscuous. I met her when she was very young and at the height of her promiscuity. She's tamed down a bunch now. She was actually a really troubled teen but turned out to be an amazing person. One of the reasons I broke up with her was because she had with over 40 guys before she reached the age of 19. That bothered the hell out of me mainly because I saw the situation as her obviously not placing the same value on as I did and her view on being distorted. However when I think about it, her next boyfriend probably will never know how promiscuous she was earlier in life and so he won't have that to bother him. It's like he'll be getting this really wonderful person that I had but without all of the emotional baggage of realizing she's slept with over 40 guys. So I ask you, should it really matter in the end how many people your gf/bf have been with when they are with you?