Just to pile on another "me too" here. I fully agree that you should limit what you do, no matter what. I, for example, always tend to overdo things. For example I once was heavily into Starcraft 2, but played so much that after just 2 weeks I had enough and haven't touched it since.

Limiting yourself can be refreshing and ensure that we will still like the things we do in 10 years.

And beeing also a fellow introvert, I have to say, not geeking around on the PC doesn't have to mean going out with friends (though it should occasionally... ;)). There are a lot of great books and websites out there with fantastic content. For example I never knew so much about the whole skeptics movement (and the science behind it) without limiting myself from geeking out.

Limiting yourself can be a great thing!