I envy those for whom this is the case. For me, I might be dead tired during the day, but I will spontaneously regain energy in the evening - enough to delay my bedtime a couple hours again.
It's absurd and somewhat dangerous - if I ever pull an all-nighter on something, it's really important I force myself to go to sleep early the next day, because I will suddenly become full of energy again come 21:00 - 23:00, go to sleep late again, and suffer further come next morning.
