So THIS is Why It's Hard To Sleep the First Time You Stay Round a New Partner's House

You're probably familiar with the situation: you stay round a new partner's house for the first time, and wake up feeling as though you've been hit by a bus. You didn't sleep well, and it wasn't ​just ​because the pair of you stayed up doing, er, other things.

But finally, science has explained why this happens ​every time​. And amazingly, it's our body's stealthy way of keeping us safe. God, we're a clever bunch.

The reason it feels like you haven't slept very well is because sub-consciously, a part of your brain is trying to stay awake. And thinking about it, it actually happens in pretty much any new sleeping environment the first couple of times you stay there.

Apparently, the left side of your brain stays alert as a means of detecting danger,​ findings published in the journal Current Biology explain. Basically, it's a bit like a 'survival mode', keeping one hemisphere more awake than the other. And even if you don't realise you're doing it, you're probably tossing and turning a lot more than you think you are.

The discovery was made recently by scientists from Brown University, who believe this level of semi-consciousness makes us more capable of jumping awake if we hear anything to alert us. And it's amazing, really. Annoying - yes, especially if you've got something important you need to feel on form for the following day, but amazing all the same.

The concept, known as the 'First-Night-Effect (FNE)', was investigated by sleep scientist Masako Tamaki and a team of researchers, who used advanced neuroimaging techniques to analyse the brain behaviour of a series of sleeping subjects.

What they discovered was an asymmetrical pattern; indicating that while one hemisphere was soundly sleeping, the other (although not fully awake) displayed a significantly higher level of activity.

So don't panic if you have a shit night's sleep the first couple of times you stay round your new boyfriend's house. It's not a sign from the gods that he's not the one, it's just your little old brain trying to keep you safe. Which is quite sweet, really.

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