My marginal cost & marginal benefit

Senario/ case study: I watched Youtube until 3am this morning.

Marginal cost: I had a worse sorethroat and headache. Couldn't eat fried sotong rings, wedges and chicken dim sum (a little bit spicy). Yes, they are part of my favourites. Didn't study at all. Haven't watch "Cinderella's Sister" episode 14.

Marginal benefit: I get to see Onew for more than 3 hours. Unexplainable satisfaction.

As a rational person, I'm sure you can easily see that the Marginal Cost of watching Youtube greatly outweigh my Marginal Benefit.

Conclusion: I regret deeply. I need more sleep. I need to work hard to finish my notes and exercises. Stay far away from my laptop and Internet. Why slash out? Because I know myself too well that I'm unable to do that. Duh...