I’ve heard that line in primary and secondary school over in Ireland too. There is a missing dimension there, where the Irish upper classes did enough oppressing of their own people. Do some research in regards to the history surrounding Dermot MacMurrough and his relationship with Henry II of England—as well as the relationship of Henry II with Pope Alexander III, who granted that king lordship of Ireland in 1172. Countries do not maintain a long-lasting united (and for the most part, mutually-beneficial) relationship via constant oppression—there was more amiability than you seem to have heard of.
The 1916 Rising had a lot of communists involved, too; even Lenin regarded that as the first communistic (albeit failed) revolution, and took it as an inspiration for his own Bolshevik revolution.
Remember that the 1800s "communism", "socialism", "liberalism" meant something different from later years
The Communism in Russia was a freak -- Marx envisioned communism in an industrial environment, not an agricultural society like Tsarist Russia
The anarchist movement in Central Europe and in Ireland was against despotic (in the case of Central Europe, the Kaiser and Tsar) and all-powerful (in the case of Ireland) rulers
This had ideas of equal opportunity and also was fighting against the autocratic sstem in Russia, the aristocratic society in Germany and England
By the standards of the 1800s, even late 1800s, the USA was a very liberal society and even "socialist" in the respect that this was a society where everyone had the opportunity to rise based on abilities (which is not what could be said about Tsarist Russia or English-ruled Ireland).
However the terms have changed and the raison-d'etre of many of these movements no longer exist (case in point -- socialism helped end child labor and 80 hour work weeks in terrible factory conditions, but the fight for 35 hour weeks is taking something to exaggeration)
Suggest you don’t waste your time.
To the true anti-English Irishman it’s always 1649 and Cromwell has just finished his massacre at Drogheda. They’re just not interested in the true history of Ireland except insofar as it can be used to demonize England. In this regard it is much like the various “studies” fields in academia, where one doesn’t really research black history, one researches the oppression of blacks by white people.
Which is not to say that there isn’t plenty of English oppression to study, only that as you say the story is more complicated.
In particular, the history of the mostly peaceful (relative to earlier and later periods) evolution of Irish/English relations from the 1880s to 1914 is generally ignored. During this period the conflict was primarily intra-Irish, with the Ulster Protestants not unreasonably violently opposed to being handed over to the tender mercies of those they had contributed to oppressing for several centuries.
In 1914 the Irish Home Rule bill was passed, which peacefully gave Ireland all most Irish people wanted. It never went into effect, due to other issues taking precedence later in the year.