[S_A_P]

Not what Im advocating. just providing a counterpoint to the argument that the only outcome to staying up late is that you are making choices that shorten life. Staying out late certainly can contribute to the OPs theory, but that isn't the only outcome. Reduction of stress, finding a community/partner/etc is definitely something that hanging out late can provide. the time of day you feel most awake doesn't mean your default is self destruction.