This has happened by me and to me on several occaisions. In my case, it happens because when
guys meet me and vice versa, there aren't always the stereotypical scenarios on which we rely to determine what the interest is, or where it goes. By saying, "
I like him as a friend," you render any attempt for intimacy that would lead to a relationship null and void, but the opposite is not always true. We can be in love with someone or have a crush on them or be dating them and their friendship is assumed; even if we're wrong, we want to think that the latter comes with the former.
As I'd expressed in guys who don't tell you they have a girlfriend, it is frustrating when you're put into a bracket, when your options are closed off for you. For me, my desire to keep exes as friends is minimal. I don't keep my exes around at all usually, and this is for both our benefit. I'm the kind of girl who when breaking up with a guy will say, " I don't want to hurt you or waste your time; this simply isn't working for me." Curt, perhaps, but I try not to string a guy along.
Then there are those in between people, people who are in themselves so amazing, inspiring, attractive, and intriguing that you cannot think of your life without them in it. You wouldn't be saying "let's just be friends" if someone hadn't crossed a boundary, or was going to very soon. Maybe you wanted all those cool things in him to add up to a perfect boyfriend, and maybe you realized that the reason why you hold them in such high regard is because you came together under the guise of friendship in the first place. This way of getting to know someone is so unique to romance. That person is more real, more intense, more open, and sometimes that leads you to think that real love exists there, love of a certain kind.