First time kid gets stitches.
First broken bone.
First time your child is literally awake for 2 or more days straight.
First time your child has decided to call you something other than mom. FYI my name is Bob according to my nonverbal autistic 6 year old.
First time you have to correct a stranger on the gender of your child once they're past the infant stage.
First time your realize that you are no longer in charge and must leave a store, restaurant, the library and so on because for whatever reason your child has decided that now is time for a meltdown.
First time your child has a meltdown in public and you actually tell the onlookers to be on their way.
First time you correct another parent on how they're buckling their child into their car seat incorrectly.
First time you yell at someone because they tell you they're sorry your child has autism, or doesn't talk, or is still in diapers at 6, or can still yes fit into the cart at the grocery store.
First time you have to explain to your pediatrician that NO giving my child 8 shots at one time is not his/her best interest.
First time you have to do the doctor's job of administering a medication because they have no idea what in hell they're doing.