Complex sentence: I was born very, very lazy and I don't always practice very long, "he said," but I must say, in my defense, that it is not so good, in a musical way, to overpractice.
Split into simpler sentences: I was born very, very lazy and I don't always practice very long. But I must say, in my defense, that it is not so good, in a musical way, to overpractice.