We all have them, but they seem to function differently for a certain segment of the population. I'll never forget that Seinfeld episode. Armpits remind me of pop culture too. To me, there is nothing more unsexy than those stinky pits. Well, maybe those stinky feet.
Arms are pretty darn functional though.
We use them for everything. In shape or out of shape they are our source of mastery in the world. Grab this, write that. Other than that arms aren't too interesting. But hands are immensely fascinating.