Sometime you just get frustrated, you have forgotten a password and you know it is saved on of your computers. However, you need to use it from another device or maybe use it with a mail client program instead of webmail. In many cases, you can just ask for a password reset, but if you have changed email since you first time create a user on that service it will not work, or it can be a service without the possibility to reset. I had the experience myself just the other day. For me it was a NAS box (network storage device), that I for the first time in ages need to access as admin instead of using it as an ordinary file service. To make things difficult I had changed IP address on the device since last login from my computer so the automatic login from the computer that had stored the password did not recognize it as a saved connection. What to do now! Maybe one of the most ordinary examples for when you need this tip I am going to give now is for users that have saved their pa