I was born in 1989 and the math is HARD some days.
Do you guys not remember how old you are year to year? Are you frequently calculating your age from your birth year instead of just adding 1 to it on your birthday?
I find that the older I get, the less I discuss or think about my age throughout the year so it gets more difficult to remember. Also, my birthday is in January so it’s over pretty quickly and I don’t tend to think about it again while I’m busy thinking about my 4 kids birthdays that are coming up, instead!
I always thought it was nuts that people don’t remember, then I turned 30 and got married to someone who has a birthday less than a year before mine. Now I have two ages to remember (that are sometimes the same) and it takes a second for me to remember which is me when asked.