I also have [email protected] (which I don’t use anymore, and just keep around), I get all kinds of private mails. Contracts, invoices, confidential material, private photos.
And of course, also automated signup mails, newsletters (which I make sure to block and report as spam, unsubscribing is a feature for newsletters that are opt-in), transactional mails etc.
People really suck at knowing what their e-mail is. The private mails are down to 1/month, the others to ~3/week, but it used to be much higher for both categories.
Oh and of course there is some kind of weird scam going on where spammers on German classifieds (Kleinanzeigen) send an e-mail to [email protected] for whatever public first and last name of the lister is, and ask if the product is still available. No link, nothing. And all sent via gmail which has by an overwhelming majority become the biggest sender of spam for me. I guess they are trying to get someone to reply and then do some manual scam or something.