Altruism and Egoism

I feel that the discussion about whether or not a person can truly be altruistic has little or nothing to do with the implementations of altruism, at least not beyond the definition of the word. The real argument only comes about when the idea is proposed that a person cannot act in a way that does not benefit them or coincide with how they wish for events to play out. Egoism itself is the problem then, and not altruism. So, when I think of egoism, I think of a person who performs actions that benefit themselves. Now, I do not believe that this means we cannot act outside of this scope. To act in favor of another over oneself must be considered. If I am in a position where I must choose to sacrifice my own state of being for the well being of another, and I choose to help that other person, then I have gone against my chance to act egoistically. Had I dismissed the well being of the other person, I would be acting for myself, and therefore would have taken my chance to be egoistic. Now, it could be said that I wanted to help the other person more than I wanted to act for myself. This can still be true without ruling out the possibility of my act being altruistic. Although I do want to do what makes me happy, the fact that I sacrifice that chance to better another person makes my act altruistic. It is impossible for a person to perform an action that they do not want to do; if they do not at least send the signals from their brain to their muscles, then they are not themselves performing the action (just as I would not say I am in control of where I go in a car if someone else is driving me; I have to at least be directly involved in the action to do it myself, ex.: I am moving of my own will because I chose to be in the car). But wanting to do something is not the only factor in whether or not an action is performed. Weighing the the wants of the other person is equally as important, at least to those of us who are not egocentric.
My summary example for this: I am walking along the seaside, enjoying the water and sunset. There is a person in distress only a few yards out into the water (someone I could easily save). I want to keep walking down the beach (as it is my reason for being there, although I might not immediately be thinking about it), but my reaction towards seeing a person in need sets off a lighting-quick series of events in my head. The first is that I stop walking. The second is that I look around to get a grasp of what is happening. The third is that I proceed with helping the person. This example is isolated from wanting to help the person; whether or not I actually want to help them is not important. What is important is that I value the life of the other human being, I weigh my desires against theirs, find that I have no reason not to assist them, and then proceed to abandon my activity in favor of theirs. This case is a little extreme, but I feel my argument can carry into situations that are not so dire and immediate. It may not be a proper sentence structure, but this next bit will attempt to describe my thoughts on the situation without having to refer to myself: "This person needs help. There appears to be only one person here who can help. The desire of another person to live and survive is paramount. An attempt to save this person must be made." No reference is made to either "I" or "want", and I wish to express the difference between objectively referring to myself in the third person as well as the distinction between a person's desires (which I believe can be purely instinctual) and a person's wants (which I believe are more directly related to instances we are trained to hope for because the results are positive). [These two issues only arise because, even objectively, I must refer to myself ("only one person here") since I am the author, and because "desire" is often used interchangeably with "want", which is not the sense in which I am using it here.]

Is altruism an idea in and of itself, or it is merely a temporary absence of egoism?
(Are humans solitary with the ability to help or symbiotic with a sense of self?)