While I agree 100% with the notion that matter is energy and energy is matter, and your example of the common photon illustrates this point nicely, I think I need to reflect on this important idea more closely to come to terms with its significance. I always read things along this line and try to grasp it, and find myself falling somewhat short. I do believe in "the force," as in Star Wars, which is a reiteration of the same conundrum. I am fascinated by the notion that all matter has its own energy, because it itself is energy. And therefore how matter and energy's relation to one another levels certain properties of the universe into a unified playing field.
Even crazier is the idea of the parallel universe consisting entirely of anti-matter. What's the theory with it? Nothing can slow down to the speed of light? Could be onto something there: I forget which it was, but not too long ago some lab research scientists were either able to create an environment colder than absolute zero, or accelerate a particle to speeds in excess of the speed of light. I don't know what this proves about the universe, but something profound, however startling, in man working hard to discovering the limits of the laws of physics, and then finding ways to surpass them. So what's next, wormhole exploration?? We can only wait and see.
About enlightenment, I am still a heavy seeker of this almighty ideal. I am hoping that death is not the only way to achieve enightenment.. but often I fear it is. More often than I care to divulge, I am left wondering why me, why life, why the universe, why anything? For what purpose do I go to work everyday? Why is it important? I know the immediacy, that my job is to help monitor contaminant levels at sites with the long-term goals of helping clean them up, or just to adjust property values according to their level of contamination, and that I need my job as a course of income, so I can eat, etc. That's the nitty gritty. What is the big picture? Where is the meaning in it all?
I struggle with the notion that life is all about having a good time. Yes, it seems that wrestling the issue of purpose can certainly take the fun out of driving a fast car, having sex, or other forms of highs that provide enjoyment and fulfillment to the moments you partake in them. It does for me. I often think why fun? Why?? The answer, I believe, is enlightenment. But I am lost in how to find it. And yet I also know that all walks of life have taught me that searching is not the way to find it. Its back to the principles of Zen. It's knowing without knowing, and knowing without knowing that you know, achieving without trying. And while I often do thing like this in every day life, it still irks me.
Pitiful example, but a valid one, none-the-less: recently I am driving my company van, eating a sandwich; when I am done, I crumple the wrapper and toss it over my shoulder, and find when I arrive at the office that it went into an empty five-gallon bucket in the rear of the van - I could have tried to do this a hundred times over and not succeeded, but without trying even trying or thinking about it, with zero intention, I achieved it.... You may call that dumb luck, and while it may very well be, but I call that something significant, a miracle of you will, in that these kinds of occurences keep my faith in things greater than the world we live in, that we cannot understand.
Anyway, it is amazing how some ancient philosophers really did know what the world is all about. I know I am stumbling with my language here... I hope I am not degrading the potency of your post with my watered-down response... it's been a long Monday.