I change my handwriting sometimes. I always have my own "style" that I go back to, but I'll see someone else's handwriting and want to replicate it because I like it. Sometimes I do it when I'm bored. I did that especially in school while I was writing notes. Every paragraph or bullet point I'd change up my handwriting to keep it interesting.
Though, most of my margins were filled with doodles instead of notes. Sometimes my hands just needed something to do, especially if it was for a class I didn't care for.