I actually have a really weird but valid excuse for bad handwriting. I had acquired a pretty decent cursive in high school, but in college, I studied Russian and began writing in Cyrillic cursive all the time. Then in the military I spent 47 weeks in total immersion Russian classes, and took notes in Cyrillic cursive for something like six hours or more a day.
All my muscle memory for writing Roman characters in cursive disappeared. If I wanted to do it now, I’d have to learn it all over again, and I’ve never had the impetus to do that.
So all I have left is my third grade block characters.
Thank God for keyboards. ;-)