What is the "something" they're giving off/putting out there?

Have any of my single readers heard this?  You ask the question, "How have they met someone already?"  Or, "How, while they were married/in a relationship, did they meet someone?"  Or, "How have they gone from relationship to relationship, without much single time in between?" 

For me, the almost universal answer has always been some variation of, "Well, they are obviously putting something out there that attracts that."  And it's never said to me in a way that indicates that's what I should be doing.  It's almost always said in a negative way, like those people are giving off something they shouldn't be.  And that what they're doing isn't healthy. 

Now, I totally agree with that.  Because, of the people I know who've recently cheated and found a relationship during/after divorce, almost instantly...I'd say they all are unhealthy. 

But here's my question.  WHAT is it they're giving off?  I mean, how am I not, to some degree, also giving that off?  I don't get it.  It really perplexes me.  To be clear, I technically don't want to be giving that "something" off, but I'd like to know what that looks like, I guess.

And that brings me back to this question.  Why the frick are they being rewarded with a relationship when they are unhealthy and should be working on themselves?  I don't get.  I don't claim to be completely emotionally healthy, none of us are.  But, I've been told by multiple people that I'm a very well adjusted, emotionally healthy person (especially considering the life experiences I've been through).  So, here I am, a fairly healthy (and normal) woman, WANTING to find a mate, but can't.  And here these other people are, NOT healthy and pretty messed up, and they've all found mates/new mates. And...they are seemingly happy.   

I don't get it.