It also depends on being able to separate out hating someone for being born 17 miles away. Having been born in and lived in and around Southampton for most of my life, plus having done my fair share of work down that end of the M27 (including now) I still find I'm able to accept the fact that, while I hope their club remains in obscurity for a very long time and they suffer miserably on the football pitch, I can't really bring myself to hate a whole population who I'll likely never meet. Plus I've had plenty of banter with Pompey supporters who are mates and/or I've worked with. Horses for courses, everyone takes the rivalry differently, but "exposure to it" is a relatively minor factor IMO.