My Mom and Aunt are Mono-Mono Twins
They have the usual call each other at the same time, buy the same dress type of things. My favorite thing is that all the grand kids call them both Grandma until they are around 5 years old, and nobody corrects them.
I remember realizing that they sat, walked slightly differently and had some different mannerisms at that age. Before that we had to look for the birthmark on their collar bone.
For me, the best part of having a mono-mono mom is that my cousin, who is a year older, has been my best friend since I was born....and we got to spend all our holidays together! A couple of lucky girls. We are in our mid 50's now, and our kids are extremely close as well.