Down.

I have been down a lot lately, and I really don't know why.

I am in love with a beautiful girl who loves me with all of her heart. She makes me smile, and laugh, and most importantly cry (not because of what she does, but because she is far away.)
I am studying something that I have a true passion for. I enjoy tramping through fields to collect samples and spending hours in the haz.mat. building at the landfill learning about chemical and community reactions.
I live in an incredible space. I have everything I could need, including inspiration, but still I find none anywhere. I have books, charts, graphs, posters, game tables, stereos, a television, and a whole assortment of other things.
I have been working out to the point where I am seeing positive changes within myself. Also, this provides me with positive energy and a sense of personal well being.
I have a nice vehicle that speeds me from place to place and gives me an excuse to clean it religiously on a weekly basis.
I have a job where I can impact the lives of my peers and provide a valuable service to my community that doesn't involve flipping burgers or selling t-shirts.
I have done away with my major vices, no more cigarette burns in my t-shirts, no more dirt being poured into my lungs. No more lazy days spent a world away with no plans to return.
I have a wonderful and playful puppy that is always excited to see me. She likes to run, and jump, and fetch, and play. If I don't pay attention to her, she will put her paw in the middle of your chest and demand that I pet her.
I have a loving and caring family that embodies the American Dream. I get along with everyone, and everyone gets along with me. We are quite the loving bunch.
I have solid friends that like to have fun. We talk, and write, and communicate, and laugh, and play.
I have a million other things going for me as well, but still.....

I feel down all the time.
What could possibly be missing?