Tired, Stupid, or Early Dementia?

Whenever I make some bad miscalculation or decision (and this happens more often than I'd like to admit) I play a little game which I like to call "Tired, Stupid, or Early Dementia." Sometimes brain tumor is thrown in there as a fourth possibility, but I assure myself that since I never get headaches, a brain tumor is unlikely. Feel free to play along and try to guess the answers.