My short tenure in the Marine Corps (20ish years) I have always been used to having our sleeves rolled up on our uniform. Once the Commandant ruled that everyone would always have their sleeves down, it did strike me a bit odd. The reason was advertised because it was to remind everyone that we had Marines still at war. Um, we all know, there are Marines at war; most of us have been there to see it firsthand.
The below article is an interesting and outlook to why the “sleeves up” has made a comeback. The Marines were famous for being known to have their sleeves up. In Somalia, the enemy would comment not to challenge the Americans with black boots or white sleeves. They were of course referring to Marines who wore distinct black leather boots and had their sleeves rolled known to the them as “white sleeves”.
Magicians entertain. The grand ones, illusionists extraordinaire, command the stage, and audience. And much of their act revolves around deception and mastery of misdirection. That is – 'hey folks, look here and not over there or look over there and not here.' In fact, misdirection is the heart of good magic. It's not uncommon for a magician to hike up coat sleeves or roll up shirt sleeves and confidently exclaim, "See, nothing up my sleeve!" Breaches of integrity are purposeful and, well, an integral part of the illusion act.