Simply refer to your password protect file that lists all your accounts (by a vague nickname) and the current version of your password in use
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Selecting passwords that are identical or easy to remember "at the time" makes no sense. If you have more than a dozen accounts, a systematic method is best. Decide on a pattern that meets most requirements (it ticks me off that some sites require an alpha character in the first position while others only accept certain punctuation characters but, alas) and then have a modification for each site. No, not rover1, rover2, rover3, what on earth would you do when you get a new dog!?! You'll have to try just a bit harder or just not go 'outside'.
The fact is that if you have logins at locations you don't recall, that is a serious exposure. Close accounts you don't use (if possible) and update those you do. I just checked and I have whittled it down to just under 60 accounts that I have to use at work. Passwords for many of these get changed regularly. About half fall under a centralized access system so I really only have to keep track of 40 or so.