<Some of us have found excitement from time to time, without the "constructive" or "great goal".

When both apply, it can be wonderful:

[“It’s an amazing experience, I’ll tell you,” Chang-Diaz said, laughing, as his crewmates waved from inside.
Their first job involved attaching a grapple hook for the space station’s 58-foot robot arm on a piece of framework that must be moved during a later assembly flight. “I’m hanging like a bat upside down, looking at the Earth,” Perrin said from the side of the station.
Chang-Diaz later experienced the upside-down sensation.
“It’s a very strange feeling to fly inverted over the Earth like this,” Chang-Diaz said while riding on the end of the space station’s arm.]

From http://msnbc.com/news/759418.asp

Marcia