Oh GOD! I hate inventory! We do the whole store twice a year were I work.
Now I will say that our store does try to make it like a fun night: catered food and drinks all night; lots of sweets, they give you a bag of goodies, like candy, to keep with you. They also make a play list of songs suggested by the workers. The inventory shifts are chosen by a drawing, and many of my fellow workers are happy to be picked. But I swear I feel more like the Hunger Games...I hate it.
I'm not a night owl, and I swear by 11pm my brain hurts. To be fair I have children, and I have to be up at 6am getting them ready for school. Between my oldest and youngest I've been getting kids up for school for 10 years now and my body is just awake at 6am, no alarm needed. So working overnights is a killer for me.
I've only had to do it once, and I hated it. The other time I was drawn I was able to get someone else to take my shift. Our next inventory is coming up in a couple of months, and I'm hoping that I will dodge that bullet again.