Hey penis owners, when was the last time you looked down at your dick? Like, really looked at it. Have you thought about its sway? Examined the way it hangs to the left or right, or pulsates up or down when erect, making its curvature distinctly, irrefutably known?

More to the point, you might wonder why exactly does your penis curve—scientifically speaking? How does it choose that path? And does it matter?

If these questions regularly occupy your brain at the urinal, you're far from alone, according to Seth Cohen, M.D., assistant professor at New York University's Department of Urology, who specializes in erectile dysfunction, penile curvature and Peyronie's disease (we'll get to that).

"Men are peno-centric," Cohen said with admirable understatement. "They're very focused on what's going on with their penis.”

But men who worry about the tilt or bend in their penis are usually fretting unnecessarily. Every male is born with a specific shape and size to their penis