Ireland being part of "the British isles"?

I'm currently living in Australia and was having a conversation with someone today who mentioned Ireland as being part of the UK, to which someone responded that it wasn't, which brought about the response "oh sorry, "the British isles" if we're being politically correct". A quick Google later and (at least according to Wikipedia) it is.

What happened to the whole 800 years of oppression and the Easter rising etc?

Full disclosure, yes I'm a Brit, but I lived in Ireland for 15 years and have an Irish wife and kids, so I'm pretty much semi-adopted Irish at this point.