I'm thinking of staying up for 3 days
Why would you want to do that? Is there a reason?
Yes, I want to test my endurance
I think that is going to be tough. You should be careful, too because it can be bad for your health.
I can't be bothered with things like what is good for my health, I will try and see how it goes.
I am sorry to hear you are not feeling concerned about your health. Don't you want to be able to feel good and well?