Interesting question! I can’t speak so specifically to the time of King John (perhaps someone else can), but I can definitely give you an overview of English attitudes to Ireland as they developed through the Medieval period and into the Early Modern. Hopefully you find it interesting all the same. There was a remarkable degree of continuity of these views over the centuries, not to say that there were no changes at all. English views of Ireland were frequently fraught with contradictions - it was both a place to be reformed and a place to be conquered, both a Kingdom and a Colony - but generally Ireland was portrayed as a wild and savage place, badly in need of English civility.

Over the course of the Medieval period a frontier ideology developed as English control became more solidly confined to certain heavily fortified border areas (referred to as ‘marches’).Yet the English never relented their claim to control the whole of Ireland. They eventually succeeded in totally subduing the country by the 17th century. This ‘success’ was very much linked to a new, more aggressive ‘settler colonial’ ideology amongst ‘New English’ Protestant settlers. A new wave of crown sponsored plantations had developed since the 16th century, and this process of land reorganisation was finally confirmed following the 1641 Rebellion which saw the final collapse of Gaelic Ireland and a new Land Settlement. The Act of Parliament which ratified this reorganisation was the so-called Adventurers' Act of 1641.

In the same way that “The West” is a myth linked to the self-fashioning of an American identity, there certainly could be some comparisons to be made. However I’ll limit my answer to what I know (ie. English colonialism in Ireland) and allow you to draw your own comparisons. I do tend to ramble once I get going on these topics lol, so if the post is too meandering or unclear then feel free to ask for some more specific clarification. I’ll try and first deal with the English perception of their Irish frontier, and then with this attitude of adventurism you ask about. To deal with Reddits character limit I’ll put the sections in replies to this post.