Pretty provocative phrase, isn't it? It's been around awhile, and I believe the original phrase by William Faulkner was 'kill your darlings' - but as you may already know, it refers to discarding anything you've written that is too precious, too crafted, not adding to the message and probably not from the heart. There's another saying that I believe originated among the Slavs - you learn all your life, and you still die stupid - which is rather a dark way of saying there's always more to be learned. I'm always aware of how much I have yet to learn about writing music and lyrics, but I am confident in saying I'm a better writer now than I was twenty years ago. I must admit that 'killing my babies' helped a lot - dumping ideas that I thought might please hypothetical critics and instead just writing what was on my mind as succinctly (and unhesitantly) as I could. The more I've taken this approach, the more I marvel at how different I feel about something I'm writing depending on whether I'm in the act of writing it versus reading it back afterwards. I'll often believe I'm writing absolute garbage while I'm in the act of writing - but that's a great way to get one's ego out of the way and write with nothing to lose. The results are almost always more fresh and vital than those carefully crafted lines one squeezes out painfully.  The truth is everybody can write, everybody can sing and hold a tune - but you do get better with practice, and the best practice avoids fear of mistakes. There's beauty in fearlessness. Then, you can fearlessly edit out your 'babies' ;) Write on!