Some of the smartest people I know tend to do this. There's one Google engineer who is a friend of mine who's incredibly talented, she graduated from a top school, straight 4.0. She did her undergrad+masters in under 4 years without taking any summer classes. Extremely well respected at work -- yet outside of work she likes to wind down and read gossip magazines.

Another friend graduated valedictorian, went to work at Goldman Sachs, and on the offtime he enjoys listening to hardcore rap and ludacris.