Control well

Today, I practiced violin for two hours and studied Math for one and a half hours.
It's very good to spend a day like this. I feel much better than yesterday or the day before yesterday. The feeling after few hours of concentration on one thing which you need to is always good.
One of the key rule to be successful is that you always control your time and not letting your ego or emotion(?) to control it.
When I control a day well, I feel sooo good!!