Good point Cleburne,
I recently read a biography on Jackson and have to agree with csamillerp. Jackson was a God-fearing man (as well as Lee) and throughout his military career had a weird quirk that helped define him as a calm general. He had the ability to stay calm and even fall asleep in the midst of a battle. The biography on him goes into detail about Jackson choosing the most inopportune moments to catch a nap but despite that he ended up being one of the best military minds in the war.
Indeed, Jackson was quite 'calm' at Beaver Dam Creek