(CNN) -- Ten years and 1.2 billion users into its existence, there's no question that Facebook has changed our lives. Whether it was an inspired vision, deft execution, a bit of dumb luck or a combination of all three, Mark Zuckerberg's social juggernaut has ingrained itself into the daily lives of digital-age users in a way that forebears like MySpace and contemporaries like Twitter could only imagine. Which is not to say it's all "likes" and "shares" and happy kid pics. As with any new (or newly discovered) technology, the impact of the end product is largely in the hands of the user. We are, after all, only human -- with all the joy and sadness, decency and ugliness that that entails.
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Facebook turns 10 next week and has undeniably changed how many of us live
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For many of those changes, there are positive and negative sides
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In the Facebook age, there's rarely such thing as a long-lost friend
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But some folks still haven't figured out etiquette of social sharing
But, with @placeholder, getting nostalgic about an old crush or flame could lead to a late-night Facebook message.