Let us enlightenment ourselves, What could be some causes of this?
Could it be stress, elaborate passwords or something else (please state what you think is a cause).
From identifying the causes, i believe we will be able to get solutions.
Only those who are giving care to sites instructing " use different passwords for different sites " , are mostly forgetting their passwords. Otherwise majority of users not forgetting.
Yes if someone is using too much bad sites or badly coded sites , for sure their passwords are compromised due to lack of coder skill to hash passwords before storing into database. Once those sites are compromised their passwords too got compromised. On such sites its better to use random passwords and store them in Chrome and take Chrome password backup by Exporting Passwords.
I am usually changing my passwords with new sets every 3-4 months. Making my own 3-4 set of passwords which i memorise first and then started changing them on those sites which have valuable asset. Rest all have same passwords from ages.