I realise that I get into a very bad state when I'm feeling really tired. I may feel awake, not having a pressing need to go to bed which is why I stay up and end up doing crazy things that I will look back upon after I wake up refreshed and think 'Omg wth did I do/say that? What for?!'

Been reading some psychology/neuroscience/behavioral economics books (Complete love! They are so interesting to read especially when I have nothing better to do like in school or on the MRT journey to and from school. Jonah Lehrer and Brafman are awesome ttm), and it seems like a likely explanation is that I have too little rest such that my prefrontal cortex doesn't really do its job in thinking through things rationally and controlling the 'emotional brain'. Apparently this is a good thing if I'm making tough decisions like what car to buy because my emotional mind is better in sorting out a lot of information (rational brain can only process 7!) and turning them into negative/positive emotions, such that if I trust my gut feeling in purchasing the car that gives me the greatest positive feelings I would be more satisfied with my decision in the long term. Unfortunately I am not exposed to such hard decisions when I'm exhausted and rational-brain-dead. Rather my emotional brain governs my actions such that I do things that I would probably not do if I had consciously thought it through. So by the time I wake up, it's too late for anything else other than 'Oh crap'