How does Chrome show links as visited even when they're not in my history?
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I've been using Chrome for years now (since 2009) and frequently notice that it shows links as visited even when I visited them far far back in the past, even years.  For example, on Google I can see all the pages I used to book my Hawaii vacation in February (6 months ago) styled as purple links.

But the weird thing is that Chrome says only 10 weeks of data is kept in history.  So then, how then does it know I visited sites way farther back then 10 weeks?  I'm curious because it would be a goldmine of data to have years of my own browsing history to look at.