What about the time you clicked on that PayPal link that wasn't really a PayPal link? "Phishing" is a term applied to either websites or emails that pretend to be something they're not in hopes of getting a user to click on something they should have ignored. This tactis is done in hopes of then getting users to provide confidential information they would have otherwise kept to themselves, typically like passwords, financial information, or other personal data. While there are security measure that fight this, the mechanics behind phishing are, unfortunately, also consistently becoming more sophisticated. Even some dedicated antivirus and business-class hosted endpoint protection suites are having trouble keeping up.
An example here is the rapidly growing trend of "inbox zero." It's actually known by a variety of names, but it refers to the practice of keeping your email inbox count at zero stored emails. Essentially, it's dealing with every email as it comes in and then deleting or archiving each one so that your inbox is always empty. This boils down to a fundamental shift in how users are utilizing their email inboxes.