Refers directly to Till Lindemann, lead singer for the GermanIndustrial band Rammstein. It refers to the fact that he has put on a little...erm...Weight and it isn't muscle. Also refers indirectly to someone who has put on a few pounds.
He looked a bit like the Tillsbury Doughboy in their video for "Mein Teil" didn't he?
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.