http://thescriptlab.com/the-formula/script-tips/795-your-screenplay-is-not-your-baby
Never refer to your script as “my baby”. If you’re guilty of this offense, clearly we know that you’re passionate about your story, which is good. But it also makes your ability to be objective with the material suspect. And you must be objective.
Subjective emotional attachments can blind you from the truth of script theme, from solving story problems, or from negotiating character differences – all of which are essential to rewriting your screenplay. And if you’re serious about being a writer, you better face up to the fact – if you haven’t already – that all writing is rewriting.
As a parent – and I know, I’m a father of three – it can be quite difficult to make the tough decisions when it comes to my own children – because they are quite literally “my babies”, and I love them unconditionally. However, unconditional love is biased. My children didn’t have to earn my love. It was just handed to them – immediately at birth. Conversely however, you can’t love your screenplay just because it exists.
So if you do have an affinity toward your screenplay, it better be because the process of writing the script itself earned that affection. You worked at it every day for 6 months or a year or longer, writing draft after draft and making the hard decisions along the way. You completed something of worth only because you busted your butt. So go ahead; admire the final product. But never go in doting what you have yet to complete. Work hard, be objective, and embrace the end result.