Irish nationalism is like when you really love your country and want it to be even better.
In Ireland, there were some people who wanted Ireland to be its own country, with its own government and leaders, instead of being part of another country called Great Britain. These people believed that Ireland should be free to make its own decisions about things like laws, taxes, and trade.
Some Irish nationalists have been fighting for this for a very long time, because they feel like Ireland should have its own cultural identity and be able to control its own destiny.