I have this same issue with one of my junk email addresses. It's pretty short, it's a famous person's last name (I was a fan), but it's not a very common last name. I've received all kinds of stuff, from many people, but one lady in particular. I only recently noticed this and when checking, I found out that this had been going on since 2008. She's used my email for: car service appointments, plane tickets, Walmart orders, forwards from her work email, turbo tax, customer support, change.org, hotel reservations, etc. Pretty much every aspect of her life has ended up in that mailbox.

I'm truly happy for her that I'm not a malicious person and when I figured it out I sent her a message. I hope she manages to stop using my email for stuff.