For a Juve fan it's mandatory to hate Inter
During the CL final, I asked some italians if this juve hate towards inter has started since the 97/98 incidents, but they told me that they have been brought up to hate Inter since they were little kids, with scarfs saying (in italian) " Inter I hate you!!"
I think the first incident was in the 60s (during the days of Sivori and Charles), when Inter were close to clinch the league. With about 3 or 4 matchdays till the end of the league, and juve having a point advantage, they had to meet at the Comunale of Turin. However there were too many supporters and the match could not be played so it was suspended. It was then decided that Inter would be given a 2-0 walk over.
However Juve protested against this decision and the decision was over ruled by the Lega Calcio. What infuriated Inter was that at the time, the president of the Lega Calcio was Umberto Agnelli (just like today Galliani is the president).
Juve went on to win the league anyway, but as a sign of protest, for the replay of the match, Inter sent their youths to play (including a young Mazzola who then scored the consolation goal from a penalty) and the game ended 9-1, with Sivori scoring 6 goals.
Since then, the hate between Juve and Inter had reached an unprecedent high, and obviouslyit rescalated back in the 90s thanks to the Iuliano-Ronaldo incident.
Hope that helps
