Sleep. It always seems to feel that we never get enough of it.
Always tired. Always trying to catch up.
If this sounds like you, don't go buying a new mattress just yet (but if you do, take a quick look at our roundup of best online mattresses). Your lack of sleep may be a cultural norm. For instance, let's spare a thought for sleepers in Singapore, who on average receive the least amount of sleep in the world - a measly 7 hours and 24 minutes.
That's according to a study published in the journal Science Advances which took a global look at how cultural and social factors affect our bedtimes.
If you're lucky enough to live in the Netherlands or New Zealand, you'll probably enjoy more than eight hours of sleep tonight.
While that difference might not seem like much, the study claims that even 30 minutes less sleep per night can have negative impacts on your health over time.
To keep track of sleep patterns, researchers turned to a smartphone app called Entrain. Using data collected from thousands of users, the team of mathematicians were able to see how gender, age, country and natural sunlight hours affect our sleep.