Quite often we will lose our password. For example I use 1 password for work, 1 password for secure sites (such as email), 1 password for retail sites (such as paypal or eBay) and another email for secondary sites (social media). Quite often I will lose a password. In those cases, I either go back to a file that has my list of passwords, attempt every last one, or fill out the lost password form.
