Yes, I've never used simsimy.
I did some digging in my mailbox.
It seems that I have/had another user (with the same email)- miertarum - activated on 21/11/2008.
I've few password reset's with that username and then, on 01/02/2011 a password reset with simsimy as username.
The even weirder part is that I got reset password email with SimSimy as username (rather than simsimy) on 17.10.11
(I'm quite sure there ware some email's I've deleted during the years)
As miertarum was a nickname I used 5 years ago and started using simsimy few years ago, I guess that at some point I registered to wp.com with another user (simsimy) and the same e-mail address. When I try to reset my wp.com password with my email, I receive SimSimy as username and when I try to reset the password with "miertarum" as user it just says the password reset mail is sent but I don't get the email.
I'm not sure if this is relevant but it is weird so I thing it's worth mentioning
Just to be clear - I've never had wp.com blog with neither simsimy nor miertarum.