This reminded me of my Be Here Now mantra, as well as my resolution to love my body as it is. If I had lived in the moment back then, instead of thinking about what I could or should be, maybe I would have enjoyed life a bit more, or experienced things more deeply. Hindsight tells me that, based on the photos I was looking at, I had nothing to worry about in terms of weight loss, but since I didn't realize that at the time, I now know that I wasted all that time and energy, which could have been focused on something more productive and enjoyable.
I realize that, no matter how much I exercise or how well I eat, my body will inevitably change over time. There's no possible way (probably not even with lots of plastic surgery!) that I will have this same body at 50. So rather than stress about it and hate myself, I hope that I will be able to embrace whatever body I have at any given time in my life. Even if I'm a little overweight, I will have to love myself and appreciate my body for all the good it does for me, because hating it will do nothing but make me depressed and destructive.
Does this ever happen to you? You look at old photos, realize you looked damn good, and wish you had appreciated what you had back then? Rather than chalk it up to "You don't know what you've got 'till it's gone," why not use this as a lesson, and learn something from it so as not to repeat the same mistakes again? Like I said, our bodies are destined to change with time, and chances are, 10 years from now you'll stumble upon a picture of yourself now and realize how good you look.
Rather than repeat this same experience over and over again, try to truly love yourself for what you have now, even if it's not the best you think you can be. Hating your body won't motivate you to eat better or exercise more. In fact, it will more than likely have the opposite effect. As I've said before in my post The Anti-Resolution Revolution, loving your body will make you want to take better care of it, and do the things that make it feel good and function at it's best. I know it's scary to consider loving a body that you know could be better, and could possibly even be the reason for health problems, but trust in the fact that thinking negatively about it will do you no good at all, and could even be detrimental.
If you're successful in truly loving your body and living in the moment, maybe in 10 years when you're looking back at old photos, you'll notice something truly wonderful...you'll be happy!