I've got a lastname.firstname Gmail Addy, which I've had for many years.
For a while I've been getting emails to firstname.lastname@example.org, for several American airline bookings and a swanky NewYork rooftop restaurant booking, amongst others.
I did a bit of digging against some of the personal details I got and eventually discovered it was a guy with a email@example.com addy ("Jon", not "John" - no "h").
I forwarded his airline booking on to him and got a grateful response. It seems he'd given his email address verbally in each case, saying "Jon" but it had been written down with the "h" as John
From other info I trawled up, I know him and his SO were expecting a baby last August. Hope it arrived OK.