So, to extend this further: how do you figure out if you are in the presence of someone to whom "it" means much the same as it does to you? Not that even the most wonderful friend or lover won't ever hurt you. But someone who values the same things, who sees things similarly or similarly enough, who isn't putting a completely different spin on the situation from your own?
As a few others have mentioned...is it mainly about taking time and maintaining sufficient detachment before getting over-invested?? How do you actually do this???
I don't think there's any one way that this happens so my experience is just one experience out of many. I met someone about a year and a half ago with whom I clicked immediately. It was definitely mutual with, I later learned, an attraction on his part. I felt something extra, even in the beginning, but because I was in another relationship, I wasn't conscious of the feelings for him. Suddenly, at a point in time when we were alone together, I realized there was something deeper going on between us. It was wonderful and I utterly trusted it. I can't think of anything I could have done to stop myself from loving him. Maybe I shouldn't have flung my heart into it but I don't have a regret about that. I would never have known him otherwise, and if you stop yourself or if you are too cautious, I feel a person might be closing down an opportunity as relationships fluctuate all the time and you never know what may be. We've bared our souls to each other, looked right down into each other's hearts, and so to not be with him and not have a possibiity to be is wrenching. We work together, and I've thought: never again will I let myself fall with someone I work with without being clear about what's going on between us. It's very hard to be clear. I would rather let things evolve naturally.