Can't play sound? The illustrated version is right below.
The full narration of the video.
The last night of a long holiday: the alarm is set, but sleep just won't come. The next day you're at your desk, and your head is still on vacation. This is what people call the post-holiday blues. First, relax: doctors say it isn't an illness. It's a common state of body and mind. And it's not just you. In a British survey of over a thousand people, more than half said that going back to work after a holiday left them low and unmotivated.
Why does this happen? The first reason hides in a little clock inside your body. This clock decides when you feel sleepy and when you feel awake. Over the holiday you went to bed late and slept in every day. So the clock got set later too. It's as if you quietly flew to another time zone. Then on the first day back, you flew home all at once. Scientists call this social jet lag.
Until the jet lag wears off, you feel drowsy, distracted, and a bit flat. The second reason: the good feeling you build up on holiday doesn't last long anyway. Studies found that about a week after returning to work, people's energy is back where it was before the break. So how do you bounce back? Trick one: pick a wake-up time and stick to it, every single day.
Once you're up, get some sunlight. Morning light tells the little clock: it's daytime, time to wind back. And by evening, you'll feel sleepy earlier. If you want to sleep earlier, move bedtime up a little each day, not by several hours in one night. Trick two: go easy on yourself for the first few days. Pick two or three small things that matter and finish them. Leave the tough jobs for a little later.
Trick three: give yourself something to look forward to. Research found that while people are waiting for a trip, they're already happier. A dinner plan for the weekend counts too. One more thing: if two weeks later you still feel low and sleep badly almost every day, don't tough it out. Go talk to a doctor. So feeling sluggish after a holiday doesn't mean you're lazy. Your little clock is still back on vacation. Give it a few days, and bring it home.
What's the hardest moment for you after a holiday? Tell me in the comments.
Feeling flat after a holiday usually means your body's little clock is still on holiday time. Give it a few days to wind back.
Put simply: you never boarded a plane, but your body still has jet lag. Scientists call it "social jet lag."

Same stink, different reaction: your brain files your own smell as familiar, and treats a stranger's as a germ alarm. Scientists tested it.

Same thermostat setting, opposite feeling. Your skin compares, your clothes change, and the vents blow hot or cold air.

Every hair grows from a tiny pot. Some pots are born sensitive to androgens, slowly shrink, and grow thinner and thinner hair.

Hair has no color of its own—cells at the root add it. When their spare supply runs out early, white hair shows up early. Usually it's in your genes.