Bump "learn to change tire so as not to fall victim to axe murderer" down a slot on your list of Life Skills—there's a far more practical one to be learnt, and TBH, you're already so good at running from your emotions not even some Freddy Krueger-Usain Bolt combo-stan could ever catch up to you. So insert "leave parties at the exact right time" instead, which is a deceptively unimpressive talent few have mastered. Here, with sound logic and even more solid math—I spent 43 minutes thinking about what to label the x- and y-axes!—we determine the best moment to make an exit. (Note: Whether that exit is Irish or not is still up for debate.)
As demonstrated by the above roller-coaster thingy (my sources tell me it's called a "parabola"), this is when you head out at, like, midnight, or 10 p.m. because you made the amateur mistakes of not eating your traditional pre-cheeky-cocktail snack of boiled eggs and not drinking a glass of water for every cheeky cocktail. No good. Depending on your condition, you might still be coherent enough to feel some FOMO, which is the deciding factor on which you should base your timing. Still better than being the last to leave, though. Never be the last to leave—or the first to arrive, for that matter.
In case you couldn't figure it out, the point is at the vertex of the night, otherwise known as everybody's properly tipsy enough to be interesting and no stemware has been broken yet. It would be nice if the curve could flatline from here, but real life doesn't work that way, and what was once fun must come down. HOWEVER, if you attempt to grab a slice now, you risk miscalculating the true height of revelry—what if it gets FUNNER while you're deciding between pepperoni and heartburn? WHAT IF SOMEONE PUTS A LAMPSHADE ON HER HEAD? You won't know because you'll be gone. And that sucks.
Which brings us to the winner, which is the second directly *after* you start feeling like "Wow, this is as good as it's gonna get." Getting up and putting your fracket on now requires staunch willpower and a certain stoicism, but remember that, in this narrative, you've just passed the climax, and the rest is the denouement. It is a sixth sense, really. Many have ignored this instinct and stayed, but that's how you end up feeling bored and lonely versus contentedly tucked in bed with your belly full of french fries, the surprise champion of drunk foods.
Of course, if you are truly gifted, you could work it out so you arrive at a second soirée that's just hit full-swing mode. One day, we shall devise some graphs for that too, but I've got to brush up on my NASA-level calculus first.