A calendar just for birthdays and anniversaries. Make the event a yearly occurring. Add the person’s name and year of event (birth, marriage, etc). Set up Tasker to put an un-dismissable event in the phone notification bar on the day of an event from this calendar.

Some people I know hate on this saying “it doesnt count because I didn’t really remember the birthday myself”. I would argue it counts more because I know my memory sucks and I set up a complex system of reminders for the people I care about. Now an increasing number are asking me to share my calendar and are leeching off me.