Dear Queenie,
I know I should have a check-up by my doctor every year, but I can never remember when the last one was, so sometimes I go longer than I should.
Any suggestions, Queenie?—Forgetful
Dear Forgetful,
If you have a digital day planner or even a wall calendar that you remember to consult, right after your check-up make a notation to remind you to make the appointment for your next one, and when you have made the appointment, make a notation of the date and time.
You might also consider connecting your annual check-up to some significant date that you do not have trouble remembering, like your birthday or an anniversary or a special holiday.