Missing Link

I caught a glimpse of my posture today in the window of Anthropology (How fitting), and discovered that I don't walk to my full evolutionary potential. My neck cranes out from my shoulders. I've know about this, and I don't think I can fix it. It's just the way my neck works. However, today my shoulders were hunched forward, and my neck was craned out to the limit. My walking posture is straight out of the Mesolithic era.

I don't know was the cause is. Self esteem? Lack of exercise? Am I Cro-Magnon? I'm good with computers and my brow ridge is only slightly pronounced, so I'm guessing it's a combination of choices 1 and 2. Ugh.