Big Iron: A firearm, specifically a revolver. Due to the thick metal used in creating old-style revolvers such as the Colt Peacemaker or the newer Ruger Blackhawk/Redhawk, and partially due to the weight of the weapon, they earned the nickname "Big Iron." This phrase became largely popular after Marty Robbins' widly successful gunfighting ballad called "Big Iron."
"No lone dared to ask his business no one dared to make the slip, the stranger there amoung them had a big iron on his hip"
While our lifespan is the number of years we will live, our healthspan is the number of healthy years we will have and our sexspan is is the number of years we will continue to be healthy enough to continue having an active sex life.
A lighthearted reaction upon receiving disappointing news of some sort. Usually something that isn't a particularly a big deal, esp. when it primarily affects someone else - sort of a mild schadenfreude. Sometimes doubled or tripled, and possibly said in a sing-songy voice for added comedic effect to imitate a muted trumpet, which is how the meme originated.