I continue to puzzle over Rand's concept of sense of life. Rand's idea is similar to that explored by Jose Ortega y Gassett in his book On Love: Aspects of a Single Theme. Ortega's essays in this book are fascinating to compare with Rand's essays on sense of life. His central concept in this context is that of "metaphysical sentiment", which I find deeply similar to Rand's ideas on sense of life.
Over time I have come to see less and less value in the concept of sense of life, at least as explicated by Rand. I cannot reconcile sense of life as individual with its basis or meaning as metaphysical. I've been coming to think that Rand wanted it both ways -- highly individualized sense of life with deep metaphysical meaning -- but I'm not sure this is possible. Perhaps one of these days I'll write an essay entitled Does Sense of Life Make Sense?.
My take on sense of life is that it there is a tension between saying (1) that sense of life is intensely personal and individual and (2) that sense of life has deep metaphysical significance. You can't have it both ways. If sense of life is metaphysical, then there could really be only a very few possible senses of life -- basically, the possible sets of answers to the metaphysical questions that Rand discusses in her essays (yea or nay to the questions whether knowledge, free choice, effective action, and joy are possible to human beings). I don't see much room for individuality there, unless it would be a function of "adding the measurements" back into those answers when you apply them to your own life -- e.g., I think that a certain special kind of joy is possible to human beings and you think a certain other kind of joy is possible. Yet this is not what we mean by an individual sense of life -- it is a certain way of facing life -- really one's personality. My sense of life is a curious amalgam of so many things -- my conscious ideas (which in turn are a mix of Objectivism, Aristotelianism, Taoism, Confucianism, Epicurus, Nietzsche, Robert Heinlein, etc. etc.), my family upbringing and their attendant cultural influences, my love of music, where I live and have lived, my wonderful wife, my friends, my work, my energy levels, and so on. All that adds up to something that is indeed unique. I don't see much metaphysics there -- sure, there's some (and more than average because I'm a philosophical person), but there's much that does not have much metaphysical significance. Rand wanted personality or sense of life to have metaphysical import, but I don't see it. Actually I've even started thinking that sense of life is a senseless notion. But I'm not quite ready to go that far.