First time I ever got naked in public was during 7th grade. I don't have a brother, and my dad was super uptight, so the only penises I'd seen up to that point were in the occasional spank mag one of my friends would stumble upon.
Anyway, I remember being incredibly nervous when we had to start showering after gym class. The problem got exacerbated when some of my classmates would openly stare at my cock, and I got called a freak more than once. Which went along with being a nerd pretty nicely. I lived in perpetual embarrassment for about, oh, 5 years or so. And don't even get me started with the "hard-on in English class" situations. Still makes me cringe.
Wasn't until college that I got comfortable flaunting my cock, and then I went to the other extreme. :smile:
Nowadays whenever anybody notices my package (which is often, considering how many times I catch people looking up) my attitude is more like, "Yeah. That's right." Much better reaction than diving behind a mailbox.