I don't know if it's just me but, how the hell do you nap?! I tried once, and I was still wide awake when my alarm that was supposed to wake me up from my hour

I don't know if it's just me but, how the hell do you nap?! I tried once, and I was still wide awake when my alarm that was supposed to wake me up from my hour long nap went off. I'd have to be really drunk, or not have slept for days in order to nap. I don't understand how people just nap on queue, I feel like I'm missing a trick here :(