Password creation has become a complicated process. We have hundreds of them and remembering them is a disaster for many of us. How about having one that is different for each website and yet always remembered?
Here is an effective way to do that.
Use the first letter of the site you are creating a password for and capitalize it. Use the last letter of that site as the last letter of the password, lower case. So if the site is Amazon.com start with A and end with n.
What you place in between will be the same for any site you use and should be at least 6 characters, contain a special character, and a number. I like to substitute numbers for obvious letters - 3 for E, 0 for o, 1 for i, 8 for B, etc.
Perhaps your dog's name is Snoopy. You could use $n00py which satisfies all the requirements and the password for Amazon would be A$n00pyn. The password for Staples would then be S$n00pys. Simple but useful.
All you need to remember is your 6 character word and you now know the passwords for all the sites you use. They will not change by themselves. You will have to open each site with the old password and locate its change password section to update them.