'the EU has been terrible to Ireland in the past'. [Bossy]
Bullshit.
Ireland has a thriving agribusiness sector, a world-leading pharmaceutical industry, motorways, regions that are not only still populated but actually being developed thanks to the EU. The farm my mother grew up on has an annual turnover of €1.2million. The difference between my cousin's children's life there in the last ten years and my mother's and her siblings' in the 1930s and 40s is so great it is almost like another universe.
On top of that, women in Ireland have reaped the benefit of EU policies on women's equality - right to work, right to own property and a bank account - in 1970 women faced a marriage bar in the Civil Service. Society as a whole has benefited from divorce legislation and gay rights legislation. All of this is guaranteed by the ECHR and the ECJ. Then there are little details like prisoners' rights and consumer protection. Oh and the GFA.
I have many cousins living in continental European countries, some of whom graduated from universities in Italy, Germany, and Sweden. I have relatives by marriage from Lithuania, Germany, and Poland. Ireland has become far less insular. I have cousins in Ireland who work for companies headquartered in other EU states. They did not have to emigrate as all but two of my grandfather's family had to.
Without the EU Ireland would be Puerto Rico, not quite another state of the US, sharing all the American negatives and not eligible for the positives. This will be the UK's fate, outside of the EU.