Have you ever stayed up late to finish off some work so that you’d be free to enjoy the weekend? Sacrificed sleep one night so you could be the life of the party the next?

When your obligations pile up, sleep is usually first on the chopping block. If you need more time to get things done, the easiest solution is to whittle down that eight-hour block of “nothingness” each night. That’s time that should rightfully be claimed back when you need it! After all, it’s not like you’re doing anything when you’re unconscious, right?

Not so fast.

Cutting into your sleep won’t just compromise your strength, speed, athletic skill, and muscle growth, there are innumerable mental side effects as well. Low sleep, it turns out, is kryptonite for your ability to socialize. (That’s if you go out at all—people with insomnia are three times more likely to skip leisure activities than those who are properly rested.)

Firstly, the sleep-deprived simply aren’t as much fun to be around. They tend to display more negative emotions and are less successful at conflict resolution, and the better the quality of sleep experienced by two spouses, the better the quality of their relationship and their social interactions.

This is because there are a lot of factors at play when someone is socializing (or at least, socializing well). It requires a brain that’s adept at empathy, recall, making value judgments, reading emotions, and thinking about future consequences, expectations, and goals. When you’re sleep-deprived, all of these qualities are turned on their heads and you become easily distracted, less creative, and less able to integrate and recall information.

A 2007 review of neurological research in Cellular and Molecular Life Science shed some more light on the subject of sleep and social skills, finding that with a decrease in sleep, we experience an increase in adenosine, which makes some brain cells less likely to fire and makes our brains less responsive to the outside world. Naturally, this compromises our ability to do well in conversation and pick up on information we get from other people. We’re also more likely to overreact to negative experiences when sleep-deprived, which makes it a lot harder to have productive interactions. There’s even strong evidence that low levels of sleep result in low levels of blood-borne oxygen reaching the brain, thereby “dimming the switch” on practically all of our neurological functions.

Finally, all those witty bon mots you’re so well known for dropping? Well, skip out on sleep and you’ll find them lacking. A sense of humor isn’t an intangible quality that’s bestowed upon us at birth (or after we finally memorize the entire 95-minute script of Anchorman). Humor requires very sophisticated, high-level cognition, and a lack of sleep decidedly inhibits it. The worst news? Real-life studies have shown that chugging caffeine might wake you up, but it won’t stimulate your appreciation for humor – and a sense of humor is widely considered the number one quality for successful socializing and even career advancement.

So if you need to lose an hour or two of sleep to make it to that party or charm the socks off of the object of your affection, you’re better off turning in on time and missing the first couple of hours at the bar. You’ll speak better, your mind will be more astute, your jokes will be more likely to land, and frankly, you’ll be worth the wait.