I think one of the most difficult thing is writing cause without mind and heart combination you can't write . Without sentiment you can't write and can't give concentrate. But once you give all of these things in your writing, then also nobody can stop you !
That is true. When you write continually, sometimes there comes a point when you have exhausted all of the vocabularies in your arsenal multiple times. In that moment, all you can to is give our heart out and let it say what it desires.