I've never skydived, I'm not keen on motorcycles and I don't drink, gamble or otherwise engage in risky behaviors. Just the same, I consider myself to be something of an adrenaline junkie. I say this because I'm a writer and if you're a writer, too, you probably know exactly what I'm talking about.
For you non-writers let me try to explain.
The writing itself is the easy, fun part. You sit down, pick up a pen or turn on a word processor and let your imagination have a field day. You, and only you, have complete control over your story from beginning to end as you write. You get to choose everything from the color of your character's eyes to the world they live in to who they fall in or out of love with. You are a God, happily creating in your own little universe.
The hard part comes after you type "The End." Now you have to let others read what you wrote, knowing full well they are going to pick it apart and criticize it from one end to the other. All that lovely control you had while writing is stripped away, given instead to your reader. Whether you ask members of your family, your writing group, or classmates to read your manuscript, you do so knowing it is going to hurt. If they're any good as critics they'll show no mercy at all for your finer feelings, nor will you want them to. As much as it might hurt to read what they have to say, all those red pen marks, strike-outs and scribbles in the margins are more valuable that gold. You will use every drop of feedback your reader provided to revise your manuscript, then send it out for review all over again, time after time, until your manuscript is as reader-centric as you can possibly make it.
Of course, knowing how important feedback is doesn't make it any easier to put your darlings out there, ripe for the killing. Because most good writers put so much of themselves into what they write accepting, much less embracing, criticism can be extremely difficult. Yet just as the skydiver digs down deep to find the courage to fling himself from the plane, if you are serious about what you write you'll keep right on jumping into the void, knowing that if you trust the reader to tell you what she really thinks, by doing so she'll help you polish your manuscript to a brighter shine than you could possibly achieve alone.