The Irish goodbye (or whatever you may call it: ghosting, the Swedish/Irish exit, etc.) is basically when you leave somewhere unannounced.
It typically happens after a night of drinking, but the somewhat stealthy move can really be used in any social setting.
So why would someone do this?
It keeps the party going. By sneaking out, you're allowing others to continue their conversation uninterrupted, which is really thoughtful and something only a good friend would do.
It also lets you leave alone. While exchanging farewells, it's pretty common for others to piggyback on your departure, but that's not possible when nobody knows you're leaving.
In other words, you're being an ideal guest by ghosting.
Now, there are, of course, personal reasons for the Irish goodbye. For instance, maybe you had a brief moment of clarity where you realized you need to leave now or something bad will happen.
Which, depending on how you want to look at it, also makes Irish exiters good party attendants because nobody likes this dude:
But the main reason for leaving without saying goodbye is because it's easy.
And getting away with doing things the easy way is one of the greatest joys in life one can experience.
It's sort of like the feeling one gets when removing one's shoes or bra after a long day.
Or probably like that high that runners are always talking about.
Plus, it's sort of fun to be sneaky and see if you can leave without being detected.
And honestly, saying goodbye can be a long process where you can potentially get caught up in multiple never-ending conversations, even though you've already expressed your desire to leave.
And let's face it, some people are just plain awkward, so it's best to avoid saying goodbye to them anyway.
So is it a little rude to not say goodbye to your friends and fellow party guests? Sure. But with the proper Irish exit, they won't even know it.
And chances are you've done this move several times before, which means it's now sort of your thing, so they should be understanding. And if they're not, then THEY'RE the bad friend.