You think about the financial things, like will I have enough to live on, but you don't think about things like who will I go on holiday with, and who will get the warrant of fitness for the car? Who will make me my morning cup of tea?
We all know lack of sleep can make you less sociable, but according to researchers, it can also make us become a "social turn-off" for those around us, making them less likely to want to interact with us.