The more you practice the more confident you get with your line and your ability to trust your hand eye coordination. And of course mistakes happen, but learning to embrace mistakes is a good thing to do. In art and in life. I also realised soon after giving up the pencil that, even though the drawings are a bit wonky and even a little dodgy at times, I love the result more, the drawings end up looking more spontaneous and authentic, which is what I strive for. Again, in art and in life. ;) Also, it's just a bloody sketch book after all, may as well give 'er!