Bingowings said:
Come AOTC, Padme being a genuine politician and an intelligent woman would continue to fancy the pants off unobtainable Obi but try and be sensible about it.
Teen Anakin (who never gave a moment's thought about Padme as a kid) would suddenly get all hormonal over her but get insanely paranoid that she fancies his guru thus shoving a wedge between them and their friendship.
It also makes for a far more believable vulnerability and turn to the dark side.