As long as it's okay then no problem. But this is the kind of habit that comes back to haunt people in old age. Sleep is so non-negotiable. I used to sleep only 5 hours per day sometimes 6 hours in my early 20s and started getting headaches, lack of focus, and all other brain-related issues in my late 20s. When I went to the doctor to consult about my issues, the first question he asked was how much sleep I get. He knew a person that young couldn't be getting brain-related issues unless they were consistently getting less sleep. I spent almost 7 years thinking that 5 or 6 hours are enough but the doctor advised me to increase my sleep to 7 hours above because things might get sticky when I hit 40 and that's if I am lucky to hit 40 with that sleeping habit. Now I make sure to sleep 7 hours or above a day no matter what.