After watching this video of an astronaut playing with a Yo-Yo in space, a few things came to mind.

Astronauts are incredibly smart people.  You don’t get to be an astronaut unless you’re damn near brilliant.  The way he describes the different aspects of physics involved with the yoyo, and how he obviously gets a kick out of that, put him on a different level than most of us.
As much as they’re doing real, important science up there, they’re still having fun.  And what’s awesome is that there are plenty of discoveries to be made while having fun, similar to this video of how water bubbles behave in zero gravity.  Every time Don Pettit plays with that yoyo, even if it is during his down time, it is being documented; they’re not just goofing around, they’re actually performing experiments!
In short, I envy the shit out of that man…
Image Source: [broadsheet]