I guy I worked with fell for one when he was selling his car online, he got an email from an interested buyer (car thief) the linked to a very good replication of the site he was selling it on. The car thief turns up and scouts the location but the give away was that he showed little interest in the car, at which point he went back and checked the email to discover the phishing.

Even trained intelligent people have momentary lapses of concentration. Imagine opening a link from email on your phone then looking away for a second while it loads, but then the address bar has disappeared and you've missed the ssl indicator.