Man I hate this too! I'm usually okay, but some days every little thing pisses me off. This is especially bad for guys (forget about girls and PMS) since we got all that testosterone flooding our system, which causes "moodiness" and a real masculine desire to punch someone in the face! Girls have more estrogen (obviously) and this affects them differently; they can be more emotional, but most likely it won't be anger or pissed-offedness (piss-offedness?!). But if you girls beg to differ, it is not your estrogen levels during your period that stereotypes you as beeing pissed, it's having to wear those damn pads between your legs for several days! Am I right? Try this guys: soak a jaycloth and wring it out. Now put it in your underwear and walk around with it there for a few days. I'd be pretty pissed too!