If like me you consider yourself lucky that at soon as your head hits the pillow you can drift off quickly but also are you like me in that on waking in the morning you still feel as if you need a good caffeine hit to get you going? Then you might care to watch this short video from Matt Walker over on TED.com – he’s a scientist researching sleep and the information just in this short film could make all the difference. For instance, did you know that caffeine has a half life of about 6 hours? Meaning 50% of the caffeine is still active in your system 6 hours later. It also means that after 12 hours 25% is still active, so that lunch time coffee is still affecting your sleep 12 hours later. And this is before he gets on to alcohol….oi!