One way of looking at networking (since I'm replying to a post on Slashdot, not writing a f*cking book) is that it lowers social and financial transaction costs.
A key part of networking is doing favours to people. You give away 'stuff' in the natural course of things that cost you nothing. You recover those photos a contact lost because their PC caught a virus. You are funny and amusing company over drinks with your store of anecdotes, building social capital. As your network grows you put A in touch with B when they can solve each other's problems without asking a finder's fee (though you might joke about 'owing you one').
And then when stuff comes up you know nothing about, you have the favours in the bank to call Joe, or Mary or whoever, and have the advice and contacts to call on to fix whatever it is in seconds, not months, and often free or at worst at non-ripoff commercial rates.
Be nice, give away what costs you nothing but don't be the doormat pushover either. People will leech off you - watch for it and find other people. Learn some basic social skills and put in the time. If you are desperately shy and uncomfortable around others, try acting or learning an instrument: it did Tom Lehrer no harm way back!
There's a whole theory of business you can look up about 'internal transaction costs', why big companies exist; because it's just more efficient that way.
Your network, apart from giving you a life in the 'get a life' sense, also gives you dramatically reduced EXTERNAL transaction costs and hugely improves your life efficiency.
If the day comes when you start out in business yourself, then you bless your network. Over, and over, and over again. And when looking for a life partner, a recommendation from a friend who knows you well beats years of hanging around in bars.
In your teens you build technical skills. In your twenties you hone them and start building social skills (if not before). In later life you focus on life skills and social abilities more and more as your undoubted technical ability becomes less important than your ability to just make stuff happen quickly. And that's why you need a network.
IMHO YMMV