Sleep deprivation can be a serious problem, which can eventually lead to very serious health issues. But you are absolutely correct, that there seems to be this urge to read, write or check just one more thing! and oh dear , I forgot to check my Twitter, Fb and LinkedIn account........ and before you know it a few more hours have passed and the sun is about to peak over the horizon. Its so easy to fall into this trap, and that's where we need to be more disciplined and as you explained "limit" and pace ourselves. Our bodies also absorb the electro magnetic radiation from our pc's and laptops, and this alone is a good reason to take a break to "go and smell the roses". Very nice and informative article and I hope people heed your advice.