Autism

I remembered when I was a kid trying to learn to hold a pen "properly" (as everyone do) I couldn't manage to do it and was holding it in my own way. Parents and teachers were trying to teach me how to hold it "properly" but it just didn't work out, I sticked to the way it was comfortable to me. The common way of holding it wasn't understandable to me and I just could not do it no matter how much I tried. Eventually adults gave up and let me be, except few more poor attempts from random teachers in school to re-teach me. I ended up with my own unique method of holding the pen and being asked from every person see my grip "why you are holding pen like that?". My handwriting wasn't very good, in school classes I would get lower grades because of it. Later as a teenager when I was "randomly" (you know) interested in calligraphy I have mastered my handwriting to a level none of those adults could ever imagine I would do, but still using the same grip I learned as a child and until now. Now when realizing myself autistic after 20+ years I thought, was my inability to learn to hold a pen in common way (as taught) a clear sign of being autistic? What is your experience with learning to hold a pen?