The best advice I've ever heard is to always try to look at things from the other person's point of view. Why would you feel bitterness at someone from another city who hadn't fully educated themselves about what happened at Hillsborough? Before you do that, ask yourself how much you know about the Ibrox stadium disaster, the Olympiacos Gate 7 disaster, the Zeebrugge ferry disaster, the Marchioness boat disaster, etc. etc. Without going in Wikipedia right now I could only give you a one or two sentence summary of what happened in those cases. How accurate would that summary be? Where would I have got that summary from - a vague recollection of a newspaper headline.
It's completely natural that people wouldn't know the truth, and would believe what they read in the papers. Now they know the truth, just be glad about that. Carrying a chip on your shoulder is pointless, you only have one life to live, people have spent 23 years day in day out fighting for this and to see people bitter about the results of that victory really bothers me.