That was exactly my thinking, can't even do 5 hours without eating haha.
But it worked out well, you don't really miss it weird enough.
As for the focus, this is the scientific reason:
Fasting increases levels of brain-derived neurotrophic factor (BDNF), a protein that interacts with neurons in the hippocampus, cortex, and basal forebrain (the parts of the brain that regulate memory, learning, and higher cognitive function — uniquely human stuff)
And as weird as this sounds, yes it actually makes you more focussed and productive, but you do have to make sure you have an outlet for this.
Wouldn't suggest doing this if you have nothing to do.