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 password for web pages like facebook or twitter, or mail. Mail is the typical thing user’s just setup once and never ever thinks about again, so when transferring the typical home user over to a new computer you need to request the password from the provider. Well as long as the old computer are still running, there might be a better way!