Every day, we try and haggle with our bodies on a number of things.
Whether it's that packet of crisps (because you've had a bad day), the chocolate bar to keep up your endorphins or the sleep deals you try and broker on a daily basis with the payoff that you'll have a lie-in on the weekend.
The harsh truth is that your body really doesn't care. It's like having a phone conversation with someone but the other person has put down the receiver and walked away.
Your body does not make deals, it does not know how to lie and it can't be fooled.
So if you don't get enough sleep - and thousands of us don't - you will pay the price eventually. Whether that's directly affecting your work, your health or your ability to function and be aware of what's going on.
When the dam breaks, it really breaks. It is a hard lesson, and one that Yahoo CEO Marissa Mayer is finding out to her misfortune, after a story ran that she was late by two hours to an important meeting at the Cannes Advertising Festival because she overslept.
She came under criticism from her bosses and has since apologised for letting the people she was meeting down. But - and we realise we don't have full access to Mayer's bedroom or diary - surely a bigger question needs to be asked here?
Only an idiot - and this may well include Mayer's boss - would think that her oversleeping means she isn't working hard enough. The problem here seems to be that she's working too hard, and at the expense of her own personal wellbeing, and her own body's ability to cope.
One thing that I feel very strongly about regarding Arianna Huffington's Third Metric ethos is that sleep is ridiculously important. And when you have a CEO's timekeeping making major news, then we have to hope that this sparks a new conversation around sleep, and that Meyer learns from this incident rather than using it as a stick to beat herself up with.
And this is far from an isolated issue. Another hard-working, successful woman came under fire recently for sleeping - this time it's supermodel of the moment, Cara Delevingne.
In an article for Vogue, Plum Sykes spent a day with Delevingne, who turned up late twice due to oversleeping - once before the interview and then after she'd had a massage.
The theme of Delevingne's sleep habits - and how much she naps - is threaded throughout the entire piece; Sykes even accuses her of 'carelessness'. Understandably, this really upset the model.
After the article was published, Delevingne tweeted: "All I can say is that I work extremely hard and 'sleeping' is proof that sometimes I work too hard. I apologise for being so ambitious."
I have to agree. Part of Delevingne's's job is hob-nobbing at parties and jetting off around the world. One quick look at her Instagram account will tell you that she doesn't do a normal 9-5 and so if anything, I applaud her for trying to get her rest where she can.
These two incidents as far as we're concerned is good old fashioned sleep shaming.
We know both of these women work damn hard, and we're pretty sure they're human and need to sleep, so let's have more of Delevingne's disco naps and not villify Mayer who clearly needs a good kip.
Please let us not return to the dark ages when boasting about how little sleep you had was a badge of honour.
Because honestly, while you think you may have the upper hand on when you decide to sleep, your body may just press the off-switch and show you who really is boss.