If I had a time machine...

I would go back and tell my 10 year old self:

• Yes, you really don't need to have very good handwriting.
• It is okay to scribble in the margins. It means you're bored, so if someone takes affront to the amount of scribbling on work turned in then it's their fault.
• Your decision that "I don't need to be good at writing since I'm good at math" was, in fact, the stupidest decision possible. You really shot future you in the foot with that one. So, thanks!