Its all a case of coincidence, curiosity and Haruhi magic. Its a combination of various factors that built up the connection between Haruhi and Kyon.
For Haruhi sitting behind Kyon in the first place, it is more of a true coincidence for me. She could have wished to meet John Smith, but I didn't think she wished to sit behind him lol
Then there was curiousity, Kyon's restlessness caused him to make contact with this pretty lady behind him. It was Kyon's initiative that sparked off a whole bunch of stuff. If Kyon didn't talk to her, she probably wouldn't have remembered about John Smith. And luckily Kyon is smart and carefully picked his topics, unlike Ryouko, programmed to behave like a normal human, asked about 'boring human topics'. Kyon was able to reach Haruhi, but not other 'normal humans'.
And for Haruhi to sit behind Kyon 7 times in a row, probably has a progressive reason. Starting from thinking that he reminds her of John Smith to finding that he actually is quite interesting and finally because she actually has a crush on him.
e.g.
May(sat behind Kyon because he reminds her of Smith)
June(Kyon is quite interesting and by sitting behind him, she could talk about SOS-dan easily)
July(If I don't talk to Kyon, school would be really boring)
August(Kyon, I must talk to him)
September(I have something I want to tell you)
October(Kyon...)
November(
)