Why is this password not good enough?
I think this answers my question: A strong password is significantly different from your previous password.:
Strong Passwords
Applications, and libraries exist for your Ubuntu system to assist in generating, or enforcing strong passwords. A strong password is defined as any password which meets the following criteria:
- At least fifteen (15) characters in length.
- Does not contain your user name, real name, organization name, family member's names or names of your pets.
- Does not contain your birth date.
- Does not contain a complete dictionary word.
Is significantly different from your previous password.
Should contain three (3) of the following character types. Lowercase Alphabetical (a, b, c, etc.) Uppercase Alphabetical (A, B, C, etc.) Numerics (0, 1, 2, etc.) Special Characters (@, %, !, etc.)
Since my current password and the new password ends with 3go!, Ubuntu won't let me reuse it.
Thank you all!
The reason it is not allowed is because you have enabled (somewhere - during installation?) to make you change every 72 days. This also disallows you from using the last password (and maybe ones before it, but it may only be the previous ones (See this comment).
Workaround:
This is clearly a strong password (or it was before you posted it), unless it had been used for another user or before for that user. I would suggest you add the user via terminal, as that doesn't have secure password requirements (but use one that isn't out there for the world to see, and please change your password soon, everyone knows it now). We can guess what your username is on your pc, probably the same as all your social networking accounts, and then your IP address can theoretically be traced through twitter of Facebook etc. NB: I'm not a hacker and I might be able to break in (I won't try), so a hacker would find it easily.
To change with terminal.
sudo adduser <username>
passwd <username>
My pronouns are He / Him