I was tired last night because the night before, I'd had a severe headache that kept me awake half the night. I tried taking something over the counter, but that didn't phase it. I ended up taking my prescription medicine. That finally worked easing the headache enough and putting me to sleep, but it left me groggy all day long. I did not want to get up yesterday morning, and I know I fell asleep at my desk at least once.