When you’re driven (in your execution) because you know where to go (with clarity what your goal is), you have a great time in your doing. And you even don’t care about sleeping only 4-4.5 hours several nights in a row.
That’s what I experienced last week. Yes, I was sleepy in the beginning but my morning walk and write (morning routine) made me awake the same way as the very clear and precise path where I was planning to go.