I'm a level headed guy also and I found no changes in my mood while taking 600 test C a week, it wasn't until coming off the stuff that I started getting side effects like achne, depression. Like people have said, if you're prone to anger you'll get angry, prone to depression you'll get depressed. I can say while on my first cycle life felt like more of a struggle because i had a busy work schedule and was in the gym everyday lifting hard as i felt like i had to as i was on gear and needed to take advantage of that and never take a day off even if i was worn down. Just take care of yourself.