would say that maybe because she's been thinking about him her whole life she thinks that she knows him.

I'd agree with that assessment. Which also makes the line about four psychiatrists even more relevant, because really, how unbalanced must a person be to think they know someone because they've been dreaming about them for years??

As far as I remember, Eleven hasn't mentioned any other companion by name, although I'm sure we were all meant to think of Donna with the line about redheads.