If whatever we do can be held against us years later, if all our impulsive comments are preserved, they can easily be combined into a composite picture of ourselves. Afraid how our words and actions may be perceived years later and taken out of context, the lack of forgetting may prompt us speak less freely and openly.
Of course, the other side of that coin is that not only will comments be preserved, but so will their context! The exact opposite trend is already in motion: rather than trusting an edited, summarized version of a conversation (say, as presented by news media), savvy web surfers go to the original transcript and see the context for themselves.
Just as Photoshop makes average people into image retouchers, YouTube makes us video distributors, and Amazon makes us book reviewers, Google and other search tools make us journalists. We’re learning to evaluate and corroborate claims, to seek out primary sources and cite them.
If every stupid comment ever made is stored, then it should no longer be a scandal to find a stupid comment someone made. As usual, human values trail behind technology. But if you want a preview, ask an 18-year-old how they evaluate a peer’s old web posts. Those in glass houses forgive smudges.