Rectal temperature at the pediatrician's office because you looked younger than your age

As the title says, anyone experienced this, and ever theorize why your temp was taken rectally during your teenage years? Likely scenario, you were in the waiting room with a bunch of much younger kids, for example you were 10 years old or older, and the other kids were 3-4 years old. And most of the time pediatricians followed the rule which says "Anyone's temperature below age 6 or 7, (so before school, or second grade) must taken rectally!".

But you probably were late maturing type, so you looked much younger, that's why the nurse didn't even bother to chose the oral thermometer just for you (especially if others were only little kids beside you in the waiting room).

Thanks for any replies!