Actually "normal" conceptually has not been around for millenia, it's origin is actually only roughly three to four hundred years old and came about during the period where societies started industrializing and jobs began having more specific requirements for whom they hired. Prior to that there wasn't really any idea of what a "normal" person was. Differently abled people were quite regular as losing function to injury, infection or disease was very common and not really seen as creating a different class of person. There's evidence of people who had pretty impairing birth defects like fused limbs who were obviously soldiers or hard labourers given their physical development. Personal mental oddities in the absence of the field of psychology categorizing things were just chalked up to being the way that person was and the way people were was myriad.

In English the word "normal" came into being in the tail end of the 17th century and was borrowed off the word for a 90 degree carpenter square to mean "theoretically fit for all kinds of work" . It's entirely a recent social invention in the grand scheme of things.