Can you function on 2 hours of sleep?

Well can you?

 That is exactly what I did last night. Mind you, it wasn't my choice. Our daughter Whitney decided that after she slept 4 hours (11PM - 3AM), that it was time to get up. Not fun. Not fun at all. I typically can get bye one 4 or 5 hours, but not 2. Come 4 o'clock in the PM, I am starting to look at the pillow like it is a close friend.