Is there any reason for an American guy like me to learn German?
Strange question. There's no reason not to learn another language. Why German?
You get to learn some stronk accents that makes you sound less of a nu-male
it's a cool language
if you want to learn a "useful" language then learn spanish
but german is still a cool as hell language
Russian's even cooler if a bit harder.
Russian is easy as fuck and more useful given where the world is headed.