Did you ever wake up from a long session online and discover that you had very little to show for it?
There's a pattern of internet use that's simple and very disturbingly unproductive. Go to you favorite network, read everything, get bored when the refresh doesn't produce anything new. Switch networks, repeat. When you've visited everything, go back to the first one and hope that there's something new.
It's a wonderful way to consume content, and since you're always looking at new things it's a way to perpetually be entertained by novelty. Subscribe to enough people, join enough networks, and you could fill your hours with new things indefinitely.
What this doesn't provide you with is a chance to create your own thing. Sure, you can share, retweet, bookmark, comment, or favorite, but that's not the same as picking an idea that's fresh and spending a few minutes from scratch presenting something new - not just new to you, but new to the world.
Creating something from nothing is much more difficult work than reading or looking what what other people have done. It takes time, and more importantly it forces you to risk making something that other people will judge. I heartily recommend getting off the social network refresh treadmill from time to time and writing something longer, even if it's not perfect.