I have had some disorganized notes for a while concerning the reality of unrequited love and how it points to truths about the nature of love in general. I keep meaning to draw them together into something unified, but I haven't been able to do it yet. So I'm just going to write out some of my random thoughts based on these notes, since I can't seem to pull it all together. Maybe through posting these I'll be able to organize and unify it a bit more, and post something drawing this out more later. I meant to relate this more directly to some points of Christian theology, but I haven't quite figured that out yet.
I'm not trying to write about masculinity here, but since I don't really have this stuff organized and I have to start somewhere, I'll start by mentioning that I wonder if there is more of a connection with unrequited love in the masculine (which does not mean it doesn't occur in women, of course), since masculinity seems to carry more the aspect of going out to the other in love. I also wonder if unrequited love is particularly problematic for the masculine, since it seems to carry an appearance of impotence, at least if one has certain views of what power is, because unrequited love may seem to imply a certain inability to control, or grasp, or possess, or even conquer.
Of course, in reality no authentic love is a matter of control or of possession. It would indicate a distortion of authentic love to try to force or control or demand a response. A love which collapses if the lover does not get what he wants can hardly be called love in the first place. Of course, any love that is received and appreciated cannot truly complain of not receiving a response, though it may lack a response in kind. In any case, however, the response can never be controlled, or we are not speaking of love. Love does not oppose freedom, but gives rise to freedom (in a quite literal and foundational sense by the way, since it is because God is Love, and loves us, that we are free). As such, love by nature accepts vulnerability.
It is perhaps unfair to place the experience of powerlessness in unrequited love in terms of experiencing a lack of control. This experience may flow from something better, in that one feels one's powerlessness to be with and for the other, to do anything for the other, indeed powerless to participate in any way in the self-gift that is the essence of love. There would be more truth in this understanding, but one still must keep in mind that any authentic love participates in the gift of self in some way. This truth does not depend on whether a particular love is enabled to take the form that you would prefer, or whether or not you are enabled to "do" anything practical and concrete for the beloved (though I would argue in any case that one person can always do something for another person in some form). Thus, common experience tells us that all human love may suffer through a similar sense of powerlessness with respect to helping the other.
In unrequited love the lover may in a sense get less in return (but then getting in return can never be at the foundation of any love), but that doesn't mean that one is not still receiving from the beloved, and receiving the beloved. What the true lover wants is not to control the response but to receive the response as a free gift. The lover must let the other be, not in the colloquial sense of that phrase which implies leaving someone alone, but literally allowing the other to be, to exist as fully and perfectly as possible as who and what they are. All love is a matter of day after day, week after week, month after month, year after year, living letting the other be, and if the love is authentic then it is precisely in this that the lover fulfills his own being, through the beloved. In this way, the existence of the beloved is already that which calls forth what the best of the lover, and it is in the first place the lover who (in giving love) is indebted to and should be grateful the beloved for his own love, and more fundamentally for the very reality that the beloved is, which enables the lover to be who he his most fully.
In this sense, unrequited love, if it really is love, is not in fact something one-sided, or something that involves giving without receiving, though the love is not returned in kind. Of course, this does not deny, but rather supports, the problematic and painful nature of this form of love. Clearly, unrequited love is unfulfilled in a large sense. If we asked anyone who loves in this way, I'm sure any such person would give anything for this love to be fulfilled through a full response of love from the other. To experience an orientation towards giving oneself entirely to another person, and to be unable to realize that total gift of self in the way one desires, is surely a tortured way of living. In a particularly obvious way unrequited love seems to be a matter of suffering, of crucifixion. Of course, it is also true that every love will be a matter of crucifixion, of death to self, in some form.
Certainly there is an obvious sense of poverty and lack in any unrequited love. Indeed, unrequited love is a love in and from a poverty in relation to the other, involving an impoverishment of the very presence of the other in a sense. Whatever is given to the lover in this love, is given only by way of not having it, and this can never be adequate for the lover, and in a sense can only be something less perfect than a fulfilled love. This is a love lived in a world torn by sin, and in a certain sense the way in which the poverty of this love has to be lived out in pain and suffering must be understood as part of one of the consequences of original sin. Such love can only be seen as not realising a fulfillment of mutual self-gift in love. However, a great poverty, a fundamental "not possessing" of the other, is at the heart of all love (even, it seems, although one must be cautious in one's terminology here, at the heart of the divine creative love, in which God both gives and respects our freedom as other than Him, though always completely related to Him.) This poverty in love can be experienced negatively, of course, but it still reflects an underlying positive and indispensable aspect of love. This itself reminds us of an important point, which I'll end with this here for now, since I have no real conclusion to offer for what I've said so far: in the state of redemption the consequences of sin themselves are caught up in the way in which the person in life is led in, by, and to love. This is true of a fulfilled mutual love as well--the consequences of sin still affect it as they do all earthly realities, and at the same time these painful consequences themselves can be caught up in the way that love leads towards the perfection and salvation through love of the persons involved.

