When I was a child, I preferred to write in secret. I think I did that for three reasons:
1.) I wrote in fear that someone was going to say, "You're only writing? Oh good - you aren't doing anything important. Come over here and help me with this." I would obey but I would think: What do you mean, nothing important? I'm creating art here! Of course, when I got back to what I was writing, I didn't want to do it anymore.
2.) I wrote in fear that someone was going to say, "Read to me what you've written so far." No, it's not ready. You don't tell someone to take you into the darkroom while the pictures are still drying. Prematurely reading my story out loud would lead to editing. Editing a story too soon led to story death.
3.) I wrote in fear that someone was going to read it before it was ready and laugh at me. I could take a lot of abuse but I can't having my creative product laughed at while still in its juvenile form.
So for these reasons, I used to write in secret. Now I find it's still a preferred way to write. I sit at a conference table while a speaker drones on and I scribble bits of dialogue in my tablet. I wait on a bench for a bus and I jot an outline in my notebook. Tomorrow, I'm going to a class where I hope there will be very few group activities so that, just like in high school or college, I can slide my pen across my notebook page and watch even one paragraph come to life. The end product will goon display but the early stages, those are just for an audience of one: me.