I would say weightlifting has made me much calmer in my day to day. If I workout in the morning, nothing else can bring me down during the day. It's just the iron against me. If I can conquer my mind telling me I can't do that I'm too weak, and repeatedly prove it wrong then, what else is my mind wrong about?

It annoys my girlfriend sometimes because nothing really bugs me or gets me really upset though she tries her best. I would say this, and stoicism are big reasons why. There are also numerous studies that show exercise reduces stress an improves your overall well being.